U.S. patent application number 11/954300 was filed with the patent office on 2008-07-31 for sound dampening passage and surface cleaning apparatus with same.
This patent application is currently assigned to G.B.D. CORP.. Invention is credited to Wayne Ernest Conrad.
Application Number | 20080179133 11/954300 |
Document ID | / |
Family ID | 39511188 |
Filed Date | 2008-07-31 |
United States Patent
Application |
20080179133 |
Kind Code |
A1 |
Conrad; Wayne Ernest |
July 31, 2008 |
SOUND DAMPENING PASSAGE AND SURFACE CLEANING APPARATUS WITH
SAME
Abstract
A surface cleaning apparatus is disclosed. The surface cleaning
apparatus comprises a fluid flow path extending from a dirty fluid
inlet to a clean air outlet and including a suction motor. At least
one cleaning stage is positioned in the fluid flow path. The
suction motor is positioned in a housing of the surface cleaning
apparatus and upstream of the clean air outlet. A sound dampening
passage is provided downstream from the suction motor and in fluid
flow communication with the clean air outlet. At least a portion of
the sound dampening passage comprises a first layer of a sound
reflecting material and an inner layer of sound absorbing material.
Such a passage is useable in other household apparatus that have an
air exit.
Inventors: |
Conrad; Wayne Ernest;
(Hampton, CA) |
Correspondence
Address: |
BERESKIN AND PARR
40 KING STREET WEST, BOX 401
TORONTO
ON
M5H 3Y2
omitted
|
Assignee: |
G.B.D. CORP.
Nassau
BS
|
Family ID: |
39511188 |
Appl. No.: |
11/954300 |
Filed: |
December 12, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60869586 |
Dec 12, 2006 |
|
|
|
Current U.S.
Class: |
181/230 |
Current CPC
Class: |
A47L 5/28 20130101; A47L
9/1608 20130101; A47L 9/165 20130101; A47L 5/32 20130101; A47L
5/225 20130101; A47L 5/365 20130101 |
Class at
Publication: |
181/230 |
International
Class: |
F01N 1/08 20060101
F01N001/08 |
Claims
1. A surface cleaning apparatus comprising: (a) a fluid flow path
extending from a dirty fluid inlet to a clean air outlet of
including a suction motor; (b) at least one cleaning stage
positioned in the fluid flow path; (c) the suction motor positioned
in a housing of the surface cleaning apparatus and upstream of the
clean air outlet; and, (d) a sound dampening passage downstream
from the suction motor and in fluid flow communication with the
clean air outlet wherein at least a portion of the sound dampening
passage comprises a first layer of a sound reflecting material and
an inner layer of sound absorbing material.
2. The surface cleaning apparatus of claim 1 wherein the passage
comprises at least a pair of opposed walls wherein each wall
comprises a first layer of a sound reflecting material and an inner
layer of sound absorbing material.
3. The surface cleaning apparatus of claim 1 wherein the sound
reflecting material is selected from plastic and metal.
4. The surface cleaning apparatus of claim 1 wherein the sound
absorbing material is selected from foam, rubber, silicone, a
member having pockets filled will one of air or fluid and
combinations thereof.
5. The surface cleaning apparatus of claim 1 wherein the sound
dampening passage comprises a longitudinally extending conduit
interior of the housing, the longitudinally extending conduit
having continuous sidewalls.
6. The surface cleaning apparatus of claim 1 wherein the sound
dampening passage is positioned exterior to the housing downstream
of the clean air outlet.
7. The surface cleaning apparatus of claim 6 wherein the sound
dampening passage comprises an outer wall of the surface cleaning
apparatus and a sound dampening panel mounted to the surface
cleaning apparatus and the sound dampening panel comprises the
first layer of the sound reflecting material and the inner layer of
sound absorbing material.
8. The surface cleaning apparatus of claim 6 wherein the sound
dampening panel is removably mounted to the surface cleaning
apparatus.
9. The surface cleaning apparatus of claim 1 wherein the sound
dampening passage extends at an angle to a direction of airflow
entering the sound dampening passage.
10. The surface cleaning apparatus of claim 9 wherein the angle is
greater than 15.degree..
11. The surface cleaning apparatus of claim 9 wherein the angle is
about 90.degree..
12. The surface cleaning apparatus of claim 1 wherein the sound
dampening passage extends linearly.
13. The surface cleaning apparatus of claim 1 wherein the sound
dampening passage has at least a curved section.
14. The surface cleaning apparatus of claim 1 wherein the sound
dampening passage has a cross sectional area transverse to its
longitudinal extent that decreases in a downstream direction.
15. The surface cleaning apparatus of claim 1 wherein the sound
dampening passage has a cross sectional area transverse to its
longitudinal extent that increases in a downstream direction.
16. A sound dampening passage positionable downstream from a fluid
flow motor comprising at least a pair of opposed walls wherein each
wall comprises a first layer of a sound reflecting material and at
least one wall has an inner layer of sound absorbing material.
17. The sound dampening passage of claim 16 wherein the sound
reflecting material is selected from plastic and metal.
18. The sound dampening passage of claim 16 wherein the sound
absorbing material is selected from foam, rubber, silicone, a
member having pockets filled will one of air or fluid and
combinations thereof.
19. The sound dampening passage of claim 16 wherein the sound
dampening passage comprises a longitudinally extending conduit
interior of a housing of the fluid flow motor having continuous
sidewalls.
20. The sound dampening passage of claim 16 wherein the sound
dampening passage is positioned exterior to a housing of the fluid
flow motor and downstream of an air outlet of the housing.
21. The sound dampening passage of claim 20 wherein the sound
dampening passage comprises an outer wall of the housing and a
sound dampening panel spaced from the housing and the sound
dampening panel comprises the first layer of a sound reflecting
material and the inner layer of sound absorbing material.
22. The sound dampening passage of claim 21 wherein the sound
dampening panel is removably mounted.
23. The sound dampening passage of claim 16 wherein the sound
dampening passage extends at an angle to a direction of airflow
entering the sound dampening passage.
24. The sound dampening passage of claim 23 wherein the angle is
greater than 15.degree..
25. The sound dampening passage of claim 23 wherein the angle is
about 90.degree..
26. The sound dampening passage of claim 16 wherein the sound
dampening passage extends linearly.
27. The sound dampening passage of claim 16 wherein the sound
dampening passage has at least a curved section.
28. The sound dampening passage of claim 16 wherein the sound
dampening passage has a cross sectional area transverse to its
longitudinal extent that decreases in a downstream direction.
29. The sound dampening passage of claim 16 wherein the sound
dampening passage has a cross sectional area transverse to its
longitudinal extent that increases in a downstream direction.
30. The sound dampening passage of claim 16 wherein each opposed
wall is provided with the inner layer of sound absorbing material.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The application claims priority from U.S. Provisional Patent
Application 60/869,586 (filed on Dec. 12, 2006), which is
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a surface cleaning apparatus and to
sound dampening passages downstream from fluid flow motors. In a
particularly preferred embodiment, the invention relates to a
surface cleaning apparatus that has a sound dampening passage that
comprises an outer sound reflecting material and an inner sound
absorbing material.
BACKGROUND OF THE INVENTION
[0003] Various types of surface cleaning apparatuses are known in
the art. Such apparatuses include vacuum cleaners such as upright
vacuum cleaners, hand or strap carryable vacuum cleaners, wet-dry
vacuum cleaners, and carpet extractors, amongst others. These
apparatuses typically include at least one suction or fluid flow
motor. Generally, the motor produces a significant amount of noise,
which can be uncomfortable to a user. For example, many full size
vacuum cleaner use a 10A-13A motor.
[0004] In some vacuum cleaner, it is known to place a filter, such
as a HEPA filter downstream from the suction motor. The filter is
provided to collect fine particulate matter that is in the air
stream that exits the vacuum cleaner, such as carbon dust. More
recently, plastic housings of varying design have been suggested to
surround a suction motor of a vacuum cleaner, so as to function as
a sound shield. These designs add weight to the vacuum cleaner and
provide an additional wall between the suction motor and the
exterior of the vacuum cleaner.
SUMMARY OF THE INVENTION
[0005] In one broad aspect, a surface cleaning apparatus is
provided. The surface cleaning apparatus comprises a fluid flow
path extending from a dirty fluid inlet to a clean air outlet and
including a suction motor. At least one cleaning stage is
positioned in the fluid flow path. The suction motor is positioned
in a housing of the surface cleaning apparatus and upstream of the
clean air outlet. A sound dampening passage is provided downstream
from the suction motor and in fluid flow communication with the
clean air outlet. At least a portion of the sound dampening passage
comprises a first layer of a sound reflecting material and an inner
layer of sound absorbing material.
[0006] Embodiments in accordance with this broad aspect are
advantageous because the sound dampening passage may reduce the
amount of sound exiting the clean air outlet. Accordingly, a user
may perceive the surface cleaning apparatus to be less noisy, and
therefore the surface cleaning apparatus may be more comfortable
and acceptable.
[0007] In some embodiments, the passage comprises at least a pair
of opposed walls wherein each wall comprises a first layer of a
sound reflecting material and an inner layer of sound absorbing
material.
[0008] In some embodiments, the sound reflecting material is
selected from plastic and metal. In some embodiments, the sound
absorbing material is selected from foam, rubber, silicone, a
member having pockets filled will one of air or fluid and
combinations thereof.
[0009] In some embodiments, the sound dampening passage comprises a
longitudinally extending conduit interior of the housing having
continuous sidewalls.
[0010] In some embodiments, the sound dampening passage is
positioned exterior to the housing downstream of the clean air
outlet. In further embodiments, the sound dampening passage extends
between an outer wall of the surface cleaning apparatus and a sound
dampening panel mounted to the surface cleaning apparatus and the
sound dampening panel comprises a first outer layer of a sound
reflecting material and the inner layer of sound absorbing
material. In some embodiments, the sound dampening panel is
removably mounted to the surface cleaning apparatus. Such
embodiments may be advantageous because a user may remove the sound
dampening panel in order to clean out the clean air outlet or a
post motor filter provided therein.
[0011] In some embodiments, the sound dampening passage extends at
an angle to a direction of airflow entering the sound dampening
passage. In further embodiments, the angle is greater than
15.degree.. In further embodiments, the angle is about
90.degree..
[0012] In some embodiments, the sound dampening passage extends
linearly. In some embodiments, the sound dampening passage has at
least a curved section. For example, it may be helical, e.g.,
extending around part or all of the outer circumference of the
surface cleaning apparatus.
[0013] In some embodiments, the sound dampening passage has a cross
sectional area transverse to its longitudinal extent that decreases
in a downstream direction. In other embodiments, the sound
dampening passage has a cross sectional area transverse to its
longitudinal extent that increases in a downstream direction. For
example, if the passage is circular in cross section, the diameter
may increase or decrease in the downstream direction. Alternately,
in some embodiments, the cross section may remain generally
constant.
[0014] In another broad aspect, a sound dampening passage
positionable downstream from a fluid flow motor is provided. The
sound dampening passage comprises at least a pair of opposed walls.
Each wall comprises a first layer of a sound reflecting material
and at least one, and preferably each opposed wall, is provided
with an inner layer of sound absorbing material.
[0015] In some embodiments, the sound reflecting material is
selected from plastic and metal. In some embodiments, the sound
absorbing material is selected from foam, rubber, silicone, a
member having pockets filled will one of air or fluid and
combinations thereof.
[0016] In some embodiments, the sound dampening passage comprises a
longitudinally extending conduit interior of a housing of the fluid
flow motor having continuous sidewalls.
[0017] In some embodiments, the sound dampening passage is
positioned exterior to a housing of the fluid flow motor and
downstream of an air outlet of the housing.
[0018] In some embodiments, the sound dampening passage extends
between an outer wall of the housing and a sound dampening panel
spaced from the housing and the sound dampening panel comprises the
first layer of a sound reflecting material and the inner layer of
sound absorbing material.
[0019] In some embodiments, the sound dampening panel is removably
mounted.
[0020] In some embodiments, the sound dampening passage extends at
an angle to a direction of airflow entering the sound dampening
passage. In some embodiments, the angle is greater than 15.degree..
In further embodiments, the angle is about 90.degree..
[0021] In some embodiments, the sound dampening passage extends
linearly. In some embodiments, the sound dampening passage has at
least a curved section.
[0022] In some embodiments, the sound dampening passage has a cross
sectional area transverse to its longitudinal extent that decreases
in a downstream direction. In other embodiments, the sound
dampening passage has a cross sectional area transverse to its
longitudinal extent that increases in a downstream direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] These and other advantages of the present invention will be
more fully and particularly understood in connection with the
following description of the preferred embodiments of the invention
in which:
[0024] FIG. 1 is a perspective view of an embodiment of a surface
cleaning apparatus in accordance with the present invention;
[0025] FIG. 2 is a perspective view of an alternate embodiment of a
surface cleaning apparatus in accordance with the present
invention;
[0026] FIG. 3 is a front elevation of the embodiment of FIG. 1;
[0027] FIG. 4 is a rear elevation of the embodiment of FIG. 1;
[0028] FIG. 5 is a top plan view of the surface cleaning head of
FIG. 1;
[0029] FIG. 6 is a cross section taken along line 6-6 in FIG.
1;
[0030] FIG. 7 is a side elevation of the embodiment of FIG. 1;
[0031] FIG. 8 is a cross section taken along line 8-8 in FIG.
1;
[0032] FIG. 9 is a side elevation of the embodiment of FIG. 1,
showing a dirt chamber in an open position;
[0033] FIG. 10 is a perspective view of the embodiment shown in
FIG. 9;
[0034] FIG. 11A is a cross section taken along line 9-9 in FIG. 1,
showing a direction of airflow through a suction motor housing;
[0035] FIG. 11B is an exploded view of the suction motor housing of
FIG. 11A; and
[0036] FIGS. 12-15 are cross sections taken along line 12-12 in
FIG. 1, showing alternate embodiments of a sound dampening
passage.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The sound dampening passage is useable in various household
appliances and tools wherein air is expelled from the apparatus. In
accordance with the resent invention, the air is drawn past a fluid
flow motor and then travels through a passage to the ambient. Part,
and preferably all, of the passage is constructed as disclosed
herein. The passage of the air through the passage reduces the
noise level perceived by a user of the apparatus. Preferably, the
passage is used in a surface cleaning apparatus. Any surface
cleaning apparatus or any configuration may be used. The upright
vacuum cleaners shown in FIGS. 1-10 merely exemplify the
application of the sound passage as an exterior part provided on an
upright vacuum cleaner. It will be appreciated that such a design
may be useful as a retrofit to existing models. Alternately, the
passage may be provided internal of the housing of the vacuum
cleaner. Further, the design may be used with an upright surface
cleaning apparatus, a canister surface cleaning apparatus, a stick
vac, a back pack vacuum cleaner, a wet/dry or shop vac style
surface cleaning apparatus, a carpet extractor, a hand or strap
carriable surface cleaning apparatus or other type of surface
cleaning apparatus.
[0038] As shown in FIGS. 1-7, surface cleaning apparatus 10
comprises a dirty fluid inlet 12, and a clean air outlet 14. A
fluid flow path extends from the dirty fluid inlet to the clean air
outlet. In the exemplified embodiments, the dirty fluid inlet 12 is
provided in a surface cleaning head 16, and clean air outlet 14 is
provided in an upright section 18. In other embodiments, clean air
outlet 14 may be provided in surface cleaning head 16. In yet other
embodiments, wherein surface cleaning apparatus 10 is not an
upright vacuum cleaner, both dirty fluid inlet 12 and clean air
outlet 14 may be provided, for example, in a main housing for the
surface cleaning apparatus.
[0039] The fluid flow path comprises a suction motor 20, and at
least one cleaning stage 22. Fluid from dirty fluid inlet 12 is
directed to the at least one cleaning stage 22. In the exemplified
embodiments, an upflow duct 24 is mounted between surface cleaning
head 16 and cleaning stage 22 for providing fluid communication
therebetween. In alternate embodiments, wherein surface cleaning
apparatus 10 is, e.g., a hand-carryable vacuum cleaner, an upflow
duct may not be provided, and the dirty fluid inlet may be in
direct fluid communication with the cleaning stage. In the
embodiment shown, fluid passes directly from dirty fluid inlet 12
to cleaning stage 22 via upflow duct 24. In alternate embodiments,
other components may be positioned between dirty fluid inlet 12 and
cleaning stage 22; for example one or more filter assemblies.
[0040] It will be appreciated that any filtration or cleaning stage
or stages known in the art may be used. Preferably, the surface
cleaning apparatus includes at least one cyclonic cleaning stage.
For example, referring to FIG. 8, in the embodiment shown cleaning
stage 22 comprises a cyclonic cleaning stage having a single
cyclone chamber 26. Chamber 26 comprises a fluid inlet 28, a dirt
or separated material outlet 30, and an air outlet 32. In alternate
embodiments, cleaning stage 22 may be, for example, a multi-cyclone
assembly, having a plurality of cyclone chambers in parallel.
[0041] A dirt chamber 34 is positioned below cleaning stage 22.
Dirt chamber 34 is in fluid communication with dirt outlet 30, and
collects dirt and/or fluid removed from air in cyclone chamber 26.
Preferably, dirt chamber 34 is openable such that dirt collected
therein may be emptied. For example, in the embodiment shown in
FIGS. 9 and 10, dirt chamber 34 is slideably removable from cyclone
chamber 26. In other embodiments, dirt chamber 34 may have a bottom
that is pivotally openable. It will be appreciated that dirt
chamber 34 may be emptied in any manner known in the vacuum cleaner
art. For example, dirt chamber 34 may be removable with cyclone
chamber 22 from the vacuum cleaner. Alternately, an openable door
may be provided.
[0042] Referring back to FIG. 8, preferably, a divider plate 36 is
associated with dirt outlet 30. For example, divider plate 36 may
comprise a disc 38 with optional support or reinforcing ribs 40
mounted, e.g., to a sidewall of dirt chamber 34 below dirt outlet
30 (see for example FIG. 9). In alternate embodiments, divider
plate 36 may be, for example, mounted above or within dirt outlet
30. It will be appreciated that divider plate may be of any design
known in the vacuum cleaner arts. For example, it may be positioned
inside a cyclone chamber wherein the dirt collection chamber is the
volume positioned below the divider plate and above the bottom of
the cyclone chamber. The divider plate may be solid or have
apertures. The divider plate may be mounted to any surface of the
dirt chamber or the cyclone chamber.
[0043] In the embodiment shown, air exits air outlet 32 and is
directed into optional filter assembly 42. Filter assembly 42 may
comprise a filter 44 housed in a filter housing 46 (see FIG. 6). In
alternate embodiments, a filter assembly may not be provided, or
more than one filter assembly may be provided or more than one
filter may be provided in filter housing 44. It will be appreciated
that any filter material or materials may be used, such as foam,
HEPA and the like.
[0044] It will be appreciated that more than one cyclonic cleaning
stage may be used. For example two cyclonic cleaning stages wherein
each stage comprises a single cyclone or two or more cyclones in
parallel may be used.
[0045] Referring to FIGS. 11A and 11B, air is directed from filter
assembly 42 towards motor 20. In the embodiments shown, motor 20 is
provided in a motor housing 48. Motor housing 48 may a separately
molded housing, as shown, or may be, for example, integral with a
housing for upright section 18. Alternatively, a housing for
another component, for example surface cleaning head 16 (FIG. 1),
may comprise motor housing 48 (i.e. motor 20 may be positioned
therein without a separate housing or with a separate housing). In
the embodiment shown, motor 20 is positioned above filter assembly
42. In alternate embodiments, motor 20 may be otherwise positioned.
For example motor 20 may be below cyclone chamber 26, or, as
previously mentioned, in surface cleaning head 16 (FIG. 1). In
other types of surface cleaning apparatus, motor 20 may be at any
desired location.
[0046] As shown by arrows A1, air that enters motor housing 48, is
directed past or through motor 20, and out of motor housing outlet
50. A sound dampening passage 52 is provided downstream from motor
20. Sound dampening passage 52 serves to reduce the amount of noise
that is generated by motor 20 that exits clean air outlet 14 and is
perceived by a user. Sound dampening passage 52 is constructed such
that, as sound waves pass through the passage, they bounce or
reflect between walls of the passage, and are dampened by the
walls, thereby reducing the decibel level of the sound produced by
the surface cleaning apparatus. Accordingly, at least a portion of
passage 52 comprises a first layer of sound reflecting material 54,
and an inner layer of sound absorbing material 56.
[0047] In the embodiments shown, passage 52 is provided downstream
of clean air outlet 14. As exemplified, clean air outlet comprises
a grill 50 on the outer surface of motor housing 48 and provides
fluid communication between motor housing outlet 50 and outlet 15
of the sound dampening passage 52. In other embodiments, passage 52
may be provided within the surface cleaning apparatus, such as
within motor housing 48, downstream from motor 20 and upstream from
clean air outlet 14. For example, the air may travel past motor 20
and then be directed in a passage internal of the surface cleaning
apparatus towards a clean air outlet that may be located distal to
motor 20. In further embodiments, more than one passage 52 may be
provided. For example, as shown in FIG. 15, a first passage 52a is
provided upstream from clean air outlet 14, and a second passage
52b is provided downstream from clean air outlet 14.
[0048] In the embodiments shown, clean air outlet 14 is directly
adjacent to passage 52 and may optionally comprise part or all of
motor housing 48. In alternate embodiments, another member may be
provided between motor housing outlet 50 and passage 52. For
example, a post-motor filter housed in a housing may be provided
adjacent or as part of clean air outlet 14, and passage 52 may be
downstream from the post motor filter.
[0049] In the embodiment of FIGS. 12 to 15, a panel 59 is
positioned to overlie clean air outlet 14 and to define a passage
between panel 59 and motor housing 48. In this exemplified
construction, passage 52 is downstream of clean air outlet 14, and
comprises a pair of opposed walls 58a, 58b. Wall 58a is the inner
surface of panel 59 and wall 58b is the outer surface of motor
housing 48. In this embodiment, passage 52 has an outlet 15 that
essentially extends around the perimeter of panel 59 since panel 59
is spaced from motor housing 48. Therefore, outlet 15 is located at
top end 66 (FIG. 2), bottom end 68 (FIG. 2), and at opposed sides
70, 72 thereof. Accordingly, passage 52 is both laterally extending
(in a direction indicated by arrow L1), and longitudinally
extending (in a direction indicated by arrow L2 (FIG. 11B)). It
will be appreciated that, in alternate embodiments, panel 59 may
abut against part or all or housing 48 except for an outlet 15 that
may be sized the same as outlet 14. It will be appreciated that
panel 59 may alternately house an airflow conduit therethrough that
comprises part or all of passage 52.
[0050] In the embodiments shown, wall 58a is provided as a sound
dampening panel 59 which is mounted to motor housing 48 via one or
more posts 61 that are received in a mount 61a (see FIG. 11B).
Sound dampening panel 59 comprises a first outer layer of sound
reflecting material 54, and an inner layer of sound absorbing
material 56. In the embodiment of FIG. 12, wall 58a further
comprises an additional outer support or reinforcing wall 63
adjacent and outwards of sound reflecting material 54. In the
embodiment of FIG. 13, support wall 63 is not provided. Wall 58b
comprises a portion of outer wall 60 of motor housing 50, and a
portion of outer wall 65 (FIG. 11A) of filter housing 46 (FIG. 7),
and comprises a single layer of sound reflecting material, which is
the wall of the housing itself. In an alternate embodiment, wall
58b may also comprise an inner layer of sound reflecting material.
It will be appreciated that any exterior surface of the surface
cleaning apparatus may be used as the inner wall 58a.
[0051] In use, sound, exemplified by stippled arrows A2, exits
motor housing outlet 50, and enters passage 52. Some of the sound
will contact sound absorbing material 56 of wall 58a, and be
absorbed. Some of the sound will pass through sound absorbing
material 56, contact sound reflecting material 54 of wall 58a, and
be reflected back into passage 52. This portion of the sound will
contact wall 58b, and again be reflected back into passage 52, and
into sound absorbing material 56 of wall 58a. Accordingly, while
the sound passes through passage 52, it will reflect back and forth
between walls 58a and 58b, and will be absorbed. Accordingly, the
sound exiting outlet 15 will be dampened. Accordingly, as the sound
passes though passage 52, sound that is not absorbed by sound
absorbing material 56 will be reflected back into passage 52 by the
sound reflecting material 54. This process will continue until the
air exits passage 52. Passage 52 may be of any desired length.
Preferably, the length is selected to reduce the sound to a desired
decibel level. It will be appreciated that some of the sound may
pass through the sound reflecting material 54 (e.g., if it is
plastic having standard wall thicknesses used for vacuum cleaners).
The sound reflecting material may be honeycombed to assist is
further reducing sound transmission through the sound reflecting
material.
[0052] It will be appreciated that if the inner wall 58b of the
passage 52 is provided with sound absorbing material. It may be the
same as the sound absorbing material on panel 59 or different.
Preferably the layer of sound absorbing material extends
continuously across each of walls 58a, 58b. It will be appreciated
that a layer of sound absorbing material may also be provided on
the outer surface of panel 59.
[0053] In the embodiment of FIG. 12, as previously mentioned, wall
58a is mounted to a panel 59, which is mounted to motor housing 48
via a post 61. In some embodiments, panel 59 may be removably
mounted to motor housing 48. This design is advantageous if outlet
14 has a post motor filter, thereby facilitating the replacement or
cleaning of the post motor filter. For example, post 61 may be
removably slidably received in mount 61a provided in motor housing
48. Alternatively, screws, welding, an adhesive or the like may be
used to mount panel 59 to the surface cleaning apparatus.
[0054] In some embodiments, rather than a pair of opposed walls,
passage 52 may comprise a longitudinally extending conduit. The
longitudinally extending conduit may be, for example, cylindrical
or rectangular. Accordingly, passage 52 may have an inlet end in
flow communication with motor 20 and a distal outlet 15. In such
embodiments, passage 52 may be provided interior of motor housing
48, or exterior of motor housing 48 and internal of the surface
cleaning apparatus or exterior of the surface cleaning apparatus.
In some such embodiments, the passage 52 may comprise a single
cylindrical layer of sound reflecting material, and a single
cylindrical layer of sound absorbing material positioned inwardly
thereof. In other such embodiments, the passage may comprise a
single cylindrical layer of sound reflecting material, and a single
layer of sound absorbing material extending along only half of the
conduit, for example in a half-pipe shape. In this embodiment, the
sound waves will reflect back and forth across the diameter of
passage 52, and will be absorbed as they pass through passage 52.
Accordingly, all walls of passage 52 may be lined with the sound
absorbing material or only part of the walls may be so lined. For
example, if the transverse cross section of passage 52 is square,
there will be a pair of opposed walls, each of which may be so
lined. If only part is so lined, it is preferred that the part that
is lined is positioned on the outward side of the passage 52. For
example, a portion of the passage 52 that faces in toward the
appliance (e.g., wall 58b that has motor 20 on the other side
thereof need not be so lined.
[0055] Preferably, in some of the above embodiments such as that
exemplified in FIG. 11A, passage 52 is configured such that it
extends at an angle to a direction of flow of the air upstream of
the passage. As exemplified in FIG. 11A, the air travels
horizontally, e.g., if the upright section of the vacuum cleaner is
oriented vertically as exemplified, as it exits outlet 14 and is
then directed to by panel 59 to travel downwardly, upwardly or
laterally. Thus, the air will undergo a change of direction of
about 90.degree. as it enters passage 52. Preferably, the change in
direction is greater than 15.degree., more preferably greater than
30.degree., and most preferably greater than 45.degree.. For
example, the change of direction may be 90.degree. plus or minus
45.degree.. In such an embodiment, the air will change direction at
an angle greater then the change of direction of the sound, thereby
causing the sound to be directed towards walls 58a, 58b.
Alternately, or in addition, passage may also cause the air to
undergo such changes of direction as it travels through passage
52.
[0056] For example, in the embodiments shown, passage 52 curves
around a portion of the outer surface of the upright section of the
vacuum cleaner and also defining a curved path extending
horizontally, and extends vertically along axis 62 (FIG. 11A). Air
entering passage 52 generally flows along an axis 64. In the
embodiment shown, axis 62 (FIG. 11A) and axis 64 are approximately
perpendicular. In other embodiments, axis 62 (FIG. 11A) and axis 64
may be otherwise angled. For example, axis 62 (FIG. 11A) and axis
64 preferably are at an angle of 15.degree. or greater relative to
each other.
[0057] In some embodiments, passage 52 may be a linearly extending
conduit having continuous sidewalls. In other embodiments, it may
be a spiral or helically extending conduit having continuous
sidewalls.
[0058] Alternately, or in addition, in some embodiments, the sound
dampening passage has a cross sectional area transverse to its
longitudinal extent that decreases in a downstream direction (see
for example, FIG. 14). In alternate embodiments, the sound
dampening passage may have a cross sectional area transverse to its
longitudinal extent that increases in a downstream direction (see
for example, FIG. 13). In alternate embodiments, the sound
dampening passage may have a cross sectional area transverse to its
longitudinal extent that is constant in a downstream direction (see
for example, FIG. 15). It will be appreciated that either of these
designs may be used if the passage has open sides (e.g., such as
when a panel 59 is used) or closed sides.
[0059] In some embodiments, as previously mentioned, more than one
sound dampening passage may be associated with motor 20. For
example, as shown in FIG. 15, in addition to the passage 52b
provided by walls 58a and 58b, an additional passage 52a is
provided interior to housing 48. The additional passage 52a is
provided by walls 76, which include an outer layer of sound
reflecting material 54 and an inner layer of sound absorbing
material 56. Walls 76 extend longitudinally and partially surround
motor 20. Accordingly, the sound generated by motor 20 will be
partially dampened in passage 52a prior to entering passage 52b.
Walls 76 may be part or all of a motor shield or housing within an
outer housing of the vacuum cleaner.
[0060] In the above embodiments, the sound reflecting material may
be selected from a variety of materials. For example, the sound
reflecting material may be a plastic, such as ABS (acrylonitrile
butadiene styrene), polycarbonate, or polyproplyene. Any hard
plastic may be used. Alternatively or in addition, the sound
reflecting material may be a metal, such as aluminum or steel. In
some embodiments, more than one reflecting material may be
selected. For example, the sound reflecting portion of wall 58a may
be a metal, and the sound reflecting portion of wall 58b may be a
plastic.
[0061] Additionally, the sound absorbing material 56 may be
selected from a variety of materials. For example, the in some
embodiments, the sound absorbing material 56 may be a foam, a
rubber, or a silicone. In alternate embodiments, the sound
reflecting material may comprise pockets filled with a gas or a
fluid. For example, the sound reflecting material may be a
bubble-wrap like material. Preferably, a soft material is used.
[0062] While the above description provides examples of the
embodiments, it will be appreciated that some features and/or
functions of the described embodiments are susceptible to
modification without departing from the spirit and principles of
operation of the described embodiments. Accordingly, what has been
described above has been intended to be illustrative of the
invention and non-limiting and it will be understood by persons
skilled in the art that other variants and modifications may be
made without departing from the scope of the invention as defined
in the claims appended hereto.
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