U.S. patent application number 10/445224 was filed with the patent office on 2004-10-07 for kitchen range hood motor housing and fan.
Invention is credited to Yeung, Peter.
Application Number | 20040194778 10/445224 |
Document ID | / |
Family ID | 4171263 |
Filed Date | 2004-10-07 |
United States Patent
Application |
20040194778 |
Kind Code |
A1 |
Yeung, Peter |
October 7, 2004 |
KITCHEN RANGE HOOD MOTOR HOUSING AND FAN
Abstract
A range hood motor housing and fan assembly for exhausting gases
generated above a cooking surface. The motor housing has top,
bottom and side surfaces defining a substantially cylindrical
chamber within which a motor and fan are housed. An air outlet is
present in the top surface. Space between the top surface and the
fan increases in the direction of rotation of the fan from one side
of the air outlet to the other side of the air outlet. The fan has
a plurality of arcuate fan blades having at least one trough
declining to the outer radial edge of the fan blade to direct any
grease draining on the blade in this direction. The motor housing
may be equipped with an air exhaust chamber projecting from the
motor housing and connected to the range hood body for recycling
air from above the cooking surface back into the cooking
environment.
Inventors: |
Yeung, Peter; (Burnaby,
CA) |
Correspondence
Address: |
Paul Smith Intellectual Property Law
330-1508 West Broadway
Vancouver
BC
V6JIW8
CA
|
Family ID: |
4171263 |
Appl. No.: |
10/445224 |
Filed: |
May 27, 2003 |
Current U.S.
Class: |
126/299R ;
126/299D |
Current CPC
Class: |
F04D 29/4233 20130101;
F04D 29/703 20130101; F04D 29/384 20130101; F04D 29/542 20130101;
F24C 15/20 20130101 |
Class at
Publication: |
126/299.00R ;
126/299.00D |
International
Class: |
F24C 015/20 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 2003 |
CA |
2,424,378 |
Claims
What is claimed is:
1. A range hood motor housing and fan assembly for exhausting gases
generated above a cooking surface comprising: an outer range hood
body; a motor housing having top, bottom and side surfaces defining
a chamber, said motor housing being mounted within said hood body;
a motor housed within said motor housing chamber; said motor
including a fan having a plurality of fan blades, said fan adapted
to rotate about said motor; an air outlet located in said motor
housing; and a space between said fan blades and said top surface
of said motor housing, said space increasing in the direction of
rotation of said fan from one side of said air outlet to the
opposite side of said air outlet.
2. The assembly of claim 1 wherein said motor housing further
comprises an upper section and a lower section, said sections being
releasably connectable to one another.
3. The assembly of claim 1 wherein said bottom surface of said
motor housing has a wall projecting into said chamber defining an
air inlet.
4. The assembly of claim 1 wherein said air outlet is located in
said top surface of said motor housing.
5. The assembly of claim 1 wherein said fan comprises: a plurality
of arcuate fan blades having front and rear faces; a basket
housing; and an outer cylindrical stabilizing element; wherein said
fan blades project radially from said basket housing to said outer
cylindrical stabilizing element.
6. The assembly of claim 5 wherein said fan blades have at least
one trough on said front face, said trough declining at an angle
from said basket housing to said stabilizing element.
7. The assembly of claim 5 wherein said side surface is
substantially cylindrical, said side surface and said stabilizing
element being substantially concentric.
8. The assembly of claim 1 wherein a portion of said top surface
and said air outlet overlaps said bottom surface.
9. The assembly of claim 1 further comprising an air exhaust
chamber connected to said motor housing.
10. The assembly of claim 9 wherein said air exhaust chamber
comprises an inlet portion, an intermediate portion and an outlet
portion, said inlet portion being connected to said air outlet and
said outlet portion being connected to an opening in said hood
body.
11. The assembly of claim 10 wherein said outlet portion has
venting slits disposed therein and aligned with said opening.
12. A fan for use within a range hood for exhausting gases
generated above a cooking surface comprising: a plurality of
arcuate fan blades having front and rear faces; a basket housing;
and an outer cylindrical stabilizing element; wherein said fan
blades project radially from said basket housing to said outer
cylindrical stabilizing element.
13. The fan of claim 12 further comprising at least one trough on
said front faces of said fan blades, said trough declining at an
angle from said basket housing to said stabilizing element.
14. The fan of claim 13 comprising two troughs, spaced one above
the other on said front faces of said fan blades.
15. A motor housing and fan assembly for a range hood for
exhausting gases generated above a cooking surface comprising: a
motor housing having top, bottom and side surfaces defining a
chamber and having an air inlet and an air outlet; a motor housed
within said motor housing chamber; said motor including a fan
having a plurality of fan blades, said fan adapted to rotate about
said motor; and a space between said fan blades and said top
surface of said motor housing, said space increasing in the
direction of rotation of said fan from a first position to a second
position.
16. The assembly of claim 15 wherein said air outlet is defined in
said motor housing between said first position and said second
position.
17. The assembly of claim 16 further comprising an air exhaust
chamber connected to said air outlet.
18. The assembly of claim 17 wherein said air exhaust chamber
comprises an inlet portion, an intermediate portion and an outlet
portion.
19. The assembly of claim 18 wherein said outlet portion has
venting slits disposed therein and aligned with an opening in said
hood body.
20. The assembly of claim 15 wherein said motor housing further
comprises an upper section and a lower section, said sections being
releasably connectable to one another.
21. The assembly of claim 15 wherein said fan comprises: a
plurality of arcuate fan blades having front and rear faces; a
basket housing; and an outer cylindrical stabilizing element;
wherein said fan blades project radially from said basket housing
to said outer cylindrical stabilizing element.
22. The assembly of claim 21 wherein said fan blades have at least
one trough on said front face, said trough declining from said
basket housing to said stabilizing element.
23. The assembly of claim 15 further comprising an air exhaust
chamber connected to said motor housing and wherein said air outlet
is defined by a ventilation wall, said vent wall being connectable
to external ducting.
Description
FIELD OF THE INVENTION
[0001] This invention relates to range hoods for use in domestic
kitchens, and more particularly to a motor housing and single fan
assembly for use in a range hood for drawing grease laden air from
above a cooking surface and venting to an external location.
BACKGROUND OF THE INVENTION
[0002] Range hoods are used above cooking surfaces to remove
grease, common odors and hazardous gases created during the cooking
process. The range hood has an outer hood body having top, bottom
and side panels defining an enclosure. A motor housing having top,
bottom and side surfaces defining a further enclosure is contained
within the outer body.
[0003] There are two basic designs for range hoods for domestic
use--a single motor design and a double motor design. An example of
the single motor design is shown in U.S. Pat. No. 4,500,331. The
'331 patent teaches a motor housing having top and bottom surfaces,
a curved outer wall and an extended end portion. There is an air
inlet in the bottom surface and an air outlet in the top surface in
the area of the extended end portion. An electric motor is mounted
to the top of the housing and a centrifugal fan attached to it. The
motor and fan are positioned above the air inlet. The space between
the outer circumference of the fan and the curved outer wall of the
housing increases in the direction of rotation of the fan, the
space being the largest in the area of the extended end portion,
thereby maximizing air flow. In order to maximize the size of the
motor and fan employed, the extended end portion and the outlet
vent located there are positioned off center within the range hood
body (the range hood being larger from side to side than from front
to back).
[0004] For individuals making greater use of grease when cooking, a
more powerful range hood, such as the double motor design, is
needed for proper removal of the grease fumes generated. In the
double motor design, the motor housing has top, bottom and
perimeter side surfaces defining an enclosure having two
substantially mirror chambers, each with an air inlet at the bottom
and an air outlet at the top. A motor and fan is positioned in each
chamber above the air inlet. The fans suck air from the cooking
area below and force it through the motor housing chambers to the
air outlet where it is directed by ventilation piping to the
outside. The space between the outer circumference of the fan and
the perimeter side surface of the respective chamber of the housing
increases in the direction of rotation of the fan, the space being
the largest in the area of the air outlet. By having two motors and
fans, greater suction power is provided. In addition, the air
outlet may be centered between the sides of the range hood.
[0005] While more powerful, the double motor design range hood is
more costly to produce. In addition to requiring two motors and
fans and the additional wiring and electronics associated with
this, the motor housing itself is larger requiring greater material
for production.
[0006] Accordingly, it is an object of an embodiment of the
invention to provide a range hood having a single motor and fan
that is more powerful than the single motor and fan design of
similar sized range hoods of the prior art.
[0007] Not all aspects of the invention necessarily address such
object. Other objects of the invention will be apparent from the
description that follows.
SUMMARY OF THE INVENTION
[0008] According to the preferred embodiment of the present
invention there is provided a range hood motor housing and fan
assembly. The assembly comprises a motor housing having top, bottom
and side surfaces defining a chamber that is mounted within a range
hood body. A motor is housed within the motor housing chamber, the
motor including a fan having a plurality of fan blades. The fan is
adapted to rotate about the motor. An air outlet is located in the
motor housing. Space between the fan blades and the top surface of
the motor housing increases in the direction of rotation of the fan
from one side of the air outlet to the opposite side of the air
outlet.
[0009] In another aspect, the motor housing further comprises an
upper section and a lower section, the sections being releasably
connectable to one another.
[0010] In yet a further aspect, the lower surface of the motor
housing has a wall projecting into the chamber defining an air
inlet. The air outlet is located in the top surface of the motor
housing.
[0011] In yet a further aspect, the fan comprises a plurality of
arcuate fan blades having front and rear faces, a basket housing,
and an outer cylindrical stabilizing element. The fan blades
project radially from the basket housing to the outer cylindrical
stabilizing element. The fan blades may have at least one trough on
their respective front faces. The troughs decline at an angle from
the basket to the stabilizing element.
[0012] In yet a further aspect the side surface is substantially
cylindrical and is substantially concentric to the stabilizing
element.
[0013] In an alternative embodiment of the assembly described
above, a portion of the top surface and of the air outlet overlaps
the bottom surface.
[0014] According to the present invention there is provided a fan
for use within a range hood for exhausting gases generated above a
cooking surface comprising a plurality of arcuate fan blades having
front and rear faces, a basket housing and an outer cylindrical
stabilizing element. The fan blades project radially from the
basket housing to the outer cylindrical stabilizing element.
[0015] According to an alternative embodiment of the present
invention, there is provided a motor housing and fan assembly as
detailed above that further comprises an air exhaust chamber. The
air exhaust chamber has an inlet portion, an intermediate portion
and an outlet portion. The inlet portion connects to the motor
housing. The outlet portion connects to an opening in the hood
body. Air from the motor housing passes through an opening into the
inlet portion, through the intermediate portion and then is vented
through venting slits in the outlet portion through the opening in
the hood body to the range hood exterior.
[0016] The foregoing was intended as a broad summary only and of
only some of the aspects of the invention. It was not intended to
define the limits or requirements of the invention. Other aspects
of the invention will be appreciated by reference to the detailed
description of the preferred embodiment and to the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention will be described by reference to the detailed
description of the preferred embodiment and to the drawings thereof
in which:
[0018] FIG. 1 is a perspective view from the bottom of a range hood
having the preferred embodiment of the motor housing and fan
assembly according to the invention;
[0019] FIG. 2 is a cross sectional view looking towards the rear of
the range hood of FIG. 1;
[0020] FIG. 3 is a side cross sectional view of the range hood of
FIG. 1;
[0021] FIG. 4 is a top plan view of the motor housing shown in
FIGS. 2 and 3;
[0022] FIG. 5 is a perspective view of the motor housing shown in
FIGS. 2 and 3;
[0023] FIG. 6 is a cross sectional view of a range hood having an
alternative embodiment of the motor housing and fan assembly;
[0024] FIG. 7 is a top plan view of the motor housing shown in FIG.
6;
[0025] FIG. 8 is a perspective view of the motor housing shown in
FIG. 6;
[0026] FIG. 9 is a cross section of the fan shown in FIG. 3;
[0027] FIG. 10 is a sectional view of the fan blade shown in FIG. 9
taken along line 10-10;
[0028] FIG. 11 is a sectional view of the fan blade shown in FIG. 9
taken along line 11-11; and
[0029] FIG. 12 is a sectional view of the fan blade shown in FIG. 9
taken along line 12-12.
[0030] FIG. 13 is a is a cross sectional view of a range hood
having a motor housing and fan assembly having an exhaust chamber
according to an alternative embodiment of the invention;
[0031] FIG. 14 is a top plan view of the motor housing and fan
assembly shown in FIG. 13;
[0032] FIG. 15 is an exploded perspective view of the motor housing
and fan assembly of FIG. 14 including a filter, cover and cap;
[0033] FIG. 16 is a top perspective view of a range hood equipped
with the motor housing and fan assembly of FIG. 15;
[0034] FIG. 17 is an exploded perspective view of a motor housing
and fan assembly according to a further alternative embodiment of
the invention; and
[0035] FIG. 18 is a top plan view of the motor housing and fan
assembly of FIG. 17.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] The present invention relates to a kitchen range hood and in
particular a motor housing and fan assembly for use in a range
hood. The preferred embodiment of a range hood 10 with a motor
housing and fan assembly according to the invention is illustrated
in FIGS. 1-3.
[0037] Range hood 10 has an outer hood body 2 having top, bottom
and side surfaces defining an enclosure. A lower panel 18 having a
wall 22 defining an air inlet may be removably connected to the
outer body 2. A motor housing 12 is mounted within the range hood
enclosure. The motor housing has a top surface 4, a bottom surface
6 and a curved side surface 8 defining a further enclosure. There
are two openings in the top surface 4 of the motor housing: an air
outlet defined by ventilation wall 24 and a housing mount 26.
Bottom surface 6 has a wall 14 projecting upwardly into the motor
housing enclosure that defines a motor housing air inlet.
Preferably both the lower panel and the motor housing air inlets
are circular and are positioned such that wall 22 and wall 14 are
in abutment when lower panel 18 is mounted in hood body 2.
[0038] The housing mount 26 is dimensioned to accommodate a motor
11, mounted within the motor housing enclosure. When motor housing
12 is mounted in place, ventilation wall 24 projects through an
opening in the top surface of the hood body and is substantially
centered between the sides as shown in FIG. 2. Both the motor 11
and the housing mount 26 are adapted to be removably attached to
the hood body 2. A fan 16 is connected to motor 11 by way of fan
cap 38. The fan 16 has an inner basket housing 30 that surrounds
the motor 11. Fan blades 17 project radially from the basket
housing connecting to a cylindrical stabilizing element 32 that
prevents the fan blades from distorting during operation. When the
motor 11 is activated, fan 16 is rotated thereby acting to draw air
through the lower panel and motor housing air inlets and into the
motor housing where it is then forced out the air outlet to be
vented to an exterior location, for example by way of a conduit
(not shown) attached to ventilation wall 24 and leading to the
exterior location.
[0039] During operation of the range hood, some of the vapourized
grease and the like in the air drawn into the motor housing
condenses on its interior surfaces. In addition to defining the air
inlet, wall 14 also acts to prevent this accumulated grease and
liquid from draining back through the air inlets to the cooking
surface below. The bottom surface 6 of the motor housing is angled
from front to back so that any accumulated liquid is directed by
gravity towards drain 48. Drain 48 is therefore located at the
lowest point of bottom surface 6 of the motor housing. As seen in
FIG. 3, a pipe 21 is attached to drain 48 in order to direct any
liquids to external grease cup 20.
[0040] In the preferred embodiment, the motor housing 12 is
substantially cylindrical, with a minimal amount of space between
the cylindrical stabilizing element 32 and the curved side surface
8. The fan is designed to force air towards the top surface 4 of
the motor housing and in the direction of rotation of the fan,
indicated by arrows in FIGS. 4 and 5. The space between the top
surface 4 of the motor housing and the top of the fan blade 74
increases in the direction of rotation of the fan starting at a
first position and ending at a second position, with the air outlet
defined between the two. The space between the top of the fan blade
74 and the top surface 4 is smallest in the area 80 adjacent the
ventilation wall on the downwind side and greatest in the area 82
adjacent the ventilation wall on the upwind side. Preferably the
sloping top surface 4 is substantially perpendicular to the side
surface 8 along any radial axis of the motor housing as shown in
FIG. 3. The housing mount 26 and motor are also cylindrical and are
concentric to side surface 8. Looking at FIG. 5, the top surface
can be seen to slope around the housing mount 26. Increasing the
space between the fan 16 and the top surface 4 of the motor housing
in this fashion maximizes the air flow.
[0041] By minimizing the space between the cylindrical stabilizing
element 32 and the curved side surface 8, the size of the fan may
be maximized. The size of the air inlets and the motor may also be
increased. The motor housing and fan assembly therefore results in
a more powerful range hood as compared to the single engine range
hoods of the prior art. In addition, costs may be reduced as
compared to the double engine range hoods, as only one motor and
fan are required.
[0042] In an alternative embodiment shown in FIGS. 6-8, additional
space is created for improved air flow. Identical reference numbers
have been used to indicate those aspects of the alternative
embodiment that are the same as the preferred embodiment described
above. Range hood 100 has a hood body 102 with vent 54 projecting
through it. The motor housing 52 is similar to that of the
preferred embodiment, but has a larger air outlet defined by vent
wall 54 that overlaps the bottom surface 106 of the motor housing.
On the upwind side of the air outlet, upper surface 104 of the
motor housing also overlaps the bottom surface 106, the overlap
decreasing in the reverse direction of fan rotation. The curved
side wall 108 has an angled portion commencing at a point (marked
as reference number 28) just above the top of the fan blades 74 up
to upper surface 104 and to the vent wall. The angling of this
portion of the side wall increases to a maximum in the area of the
air outlet. The additional space created by this angling allows a
greater volume of air to be pushed through the motor housing during
operation. However, this alternative embodiment is more costly to
manufacture. Preferably, the motor housing has an upper section 62
and a lower section 68 that are removably connectable at joint 50.
Should a user need to remove the fan 16, or wish to clean the
inside of the motor housing, lower section 68 may simply be
removed. The joint 50 may be comprised of a Y-shaped cooperating
projection 40 on one side of the joint, into which the edge 60 of
the side of the lower section is inserted. Cooperating projection
40 is angled inward at the tips of the Y to provide guidance and
ensure proper insertion of edge 60. The cooperating projection 40
and edge 60 are sized to provide a snug friction fit between the
pieces when connected.
[0043] Alignment pins or protrusions 42 are placed at intervals
around the perimeter of the motor housing 12, as shown in FIG. 5.
The alignment pins 42 are positioned on the outside surface of the
edge 60 to provide guidance as to how far the two housing sections
62, 68 have to be pushed together to ensure a tight fit. The
sections are pushed together until cooperating projection 40 abuts
alignment pins 42. The alignment pins 42 also provide a visual
guide, allowing visual inspection of the housing to ensure it is
properly reassembled.
[0044] Preferably, some form of additional restraints are spaced at
intervals around the perimeter of the housing 12 to ensure that the
upper and lower sections 62, 68 of the housing 12 stay in place
once connected. As shown in FIG. 5 the restraint may comprise a
pair of reinforcing pins 46 and a reinforcing strap 44. The pairs
of reinforcing pins are spaced about the periphery of the curved
surface 8, with one pin integral with the upper section 62 and the
other pin integral with the lower section 68. The reinforcing strap
48 is dimensioned so that when the upper and lower sections are
connected, the reinforcing strap 48 may slide over the pins 46. The
reinforcing strap 48 may then be locked into place by insertion of
cotter pins (not shown), or a similar locking mechanism such as a
cable tie or twist tie, into grooves in reinforcing pins 46.
Alternatively, reinforcing pins 46 could take the form of
self-locking pins or bolts, in which case reinforcing strap 48
would be replaced by nuts. It is contemplated that other restraints
would also work.
[0045] Preferably, the motor housing 12 is made of plastic, with
pins 42 and 46 molded and integral to the housing. However, the
motor housing may also be constructed of metal and if so, the pins
42 and 46 will preferably be welded onto the side of the upper and
lower housing sections 62, 68. Such fabrication will provide the
strongest fastening means to reinforce the connection between upper
section 62 and lower section 68.
[0046] Typically only a very small amount of grease accumulates on
a fan as most is dispersed by means of the centripetal force of the
rotating fan. However, because the air is being forced against the
top surface of the motor housing, some grease may drip down. Grease
will also accumulate on the interior of the vent wall and will drip
down after the range hood has been turned off. In order to prevent
any grease from dripping back down through the air inlets, the fan
blades act as grease catchers. This is best illustrated in FIGS.
10-12. Preferably the blades 17 of the fan 16 are arcuate and
positioned so that the top surface 74 of one fan blade overlaps the
lower surface 72 of the adjacent fan blade. Grease dripping from
the air outlet or the top surface of the motor housing will land on
the front face 67 of the fan blade 17. Two troughs 64, 70 on the
front face 67 angle downward from the inner basket housing 30
towards the cylindrical stabilizing element 32. Grease on the fan
blade will be directed by the troughs to outer perimeter of the
motor housing where it may drip onto the bottom surface of the
motor housing, eventually draining out to external grease cup 20.
Minimal grease will accumulate on the back face 65 of the fan blade
17. That grease that does attach to the fan during operation will
be forced radially outward by the centripetal force from the
rotating fan. Cylindrical stabilizing element 32 is a circular
band, preferably metal, providing structural rigidity to the
blades. Any grease collecting on element 32 will drain to the floor
of lower surface 6.
[0047] While both the preferred and alternative embodiments have
been shown with a protective fan grill 34 and a fan drain cap 36
connected to the lower panel 18, it is also contemplated that a
filter could be used. The filter would provide further protection
from grease dripping back down to the cooking surface below the
range hood however would limit the amount of air drawn into the
housing as compared to a range hood without the filter.
[0048] A further alternative embodiment is shown in FIGS. 13-16.
Not all homes are equipped with the appropriate ducting to
accommodate the range hood of the preferred embodiment.
Accordingly, in addition to the elements described in relation to
the preferred embodiment including air outlet 240, range hood 200
is also equipped with a further air exhaust chamber 220. Air
chamber 220 allows for the recycling of air drawn into the range
hood back into the room.
[0049] Air exhaust chamber 220 extends from opening 272 in wall 274
in the top section 204 of the motor housing. Air chamber 220 has an
inlet portion 250, and intermediate portion 260 and an outlet
portion 224 having openings in the form of venting slits formed
therein. Preferably, inlet portion 250 extends out past the outer
radial edge 208 of the motor housing and intermediate and outlet
portions 260, 224 are adjacent the perimeter 208 of the motor
housing as shown best in FIG. 14. Outlet portion 224 is mounted
under the top surface of hood body 202 in alignment with an opening
203 in the hood body such that gases may be recycled out of the
range hood to the range hood exterior.
[0050] Because range hood 200 may be operated in two different
ways, it may be equipped with a filter 206 and a fan grill 34. The
user may then select how they would like to use the range hood.
Should they wish to attach it to appropriate ducting for external
ventilation of gases, ducting is attached to outlet 240. Filter 206
may or may not be used depending on the user's preference. If no
filter is present, fan grill 34 and grease cap 36 provide a level
of safety for the user. Cover 270 is placed over opening 272 in
order to prevent air from entering air chamber 220 so that all air
drawn into the motor housing is forced out the air outlet 240 and
the attached ducting. It is also contemplated that cover 270 could
form an integral part of wall 274 but having a weakened break-away
seam so that if desired it may be removed as discussed below.
[0051] A user may also adapt range hood 200 for use as an air
recycler. Preferably the portion of the motor housing defining air
outlet 240 has a weakened break-away seam 228 to provide for the
easy separation of the protruding portion 254 from the top of the
range hood body as shown in FIG. 13. Seam 228 is preferably at or
below the level of the top surface of the hood body. Preferably
seam 228 is punched into the material of the motor housing. The
motor housing is painted after punching, preferably with a
non-stick coating, which seals any gaps in the material along the
seam. After knocking off protruding portion 254, plate 262 having a
cylindrical cap 264 is used to block outlet 240. Cylindrical cap
264 is dimensioned to fit within outlet 240 and to prevent the
escape of gases through outlet 240. Once the range hood is mounted
in place below a cabinet, plate 262 is held firmly in place between
the cabinet and the range hood. Gases passing through the motor
housing enter air chamber 220 through opening 272, passing first
through inlet portion 250 followed by intermediate portion 260 and
finally exiting through the venting slits in outlet portion 224.
Preferably, the bottom surface of the air chamber is sloped from
the outlet portion to the inlet portion so that any grease
collecting within the interior will drain back to the motor housing
and out to the grease cup.
[0052] A further alternative embodiment is shown in FIGS. 17 and
18. In this embodiment, motor housing 300 is adapted solely for use
in recycling air back into the room by way of air chamber 220.
Motor housing 300 has a top surface 304 that spirals about housing
mount 26 commencing at a first radial position 282 and terminating
at a second radial position 280. The second radial position 280 is
located above the first radial position 282 and an outlet opening
is formed between the two. The inlet portion 250 of the air chamber
220 projects from the outlet opening. In order to reduce the amount
of grease accumulating in the motor housing and air chamber, the
motor housing 300 is equipped with a charcoal filter 206.
[0053] It will be appreciated by those skilled in the art that the
preferred and alternative embodiments have been described in some
detail but that certain modifications may be practiced without
departing from the principles of the invention.
* * * * *