U.S. patent number RE40,818 [Application Number 11/117,773] was granted by the patent office on 2009-07-07 for blower housing with maximized interior spacing.
Invention is credited to William Stuart Gatley, Jr..
United States Patent |
RE40,818 |
Gatley, Jr. |
July 7, 2009 |
Blower housing with maximized interior spacing
Abstract
A blower for a high efficiency furnace is provided with an
increased interior space for accommodating an impeller of maximum
practicable diameter. The blower includes a blower motor and a
blower housing having a bottom piece and a top piece assembling
with the bottom piece to define an interior of the blower housing.
The top piece includes an annular lower support portion for
supporting the blower motor and an annular upper portion extending
above and around the lower portion. The upper portion has an outer
peripheral edge and lugs extending outward beyond the outer
peripheral edge. The lugs have lug holes to receive mechanical
fasteners to secure the blower housing to an external device. The
head of the mechanical fasteners are positioned above the lugs on
the upper portion of the top piece. In this arrangement the
diameter of the bottom piece is not limited by a need to
accommodate spacing for the head of the mechanical fastener.
Additionally, the top piece and bottom piece have interlocking
internal seals that provide positive engagement when the blower
housing is assembled.
Inventors: |
Gatley, Jr.; William Stuart
(Cassville, MO) |
Family
ID: |
24613663 |
Appl.
No.: |
11/117,773 |
Filed: |
April 28, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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09651650 |
Aug 30, 2000 |
6386123 |
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Reissue of: |
10127958 |
Apr 23, 2002 |
06553923 |
Apr 29, 2003 |
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Current U.S.
Class: |
110/162; 415/206;
415/213.1 |
Current CPC
Class: |
F04D
29/4226 (20130101); F04D 29/626 (20130101); Y10S
425/047 (20130101) |
Current International
Class: |
F03D
11/04 (20060101); F03B 11/00 (20060101) |
Field of
Search: |
;415/213.1,214.1,182.1,203,206,224 ;454/16
;110/205,206,214,297,147,162 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Rinehart; Kenneth
Attorney, Agent or Firm: Thompson Coburn LLP
Parent Case Text
This application is a continuation of patent application Ser. No.
09/651,650, filed Aug. 30, 2000, now U.S. Pat. No. 6,386,123 and
presently pending.
Claims
What is claimed is:
.[.1. A blower for a climate control device having a surface with a
plurality of mounting holes arranged in a pattern on the surface
for mounting the blower to the surface of the device, the blower
comprising: a blower housing top piece having a peripheral edge
that extends around the top piece, a plurality of lugs that project
outwardly from the peripheral edge with each lug having a lug hole;
a blower housing annular wall having a volute shape with a
discharge pipe projecting from the annular wall, the annular wall
extending around the peripheral edge of the top piece and being
dimensioned to be positioned on the device surface inside the
pattern of the plurality of mounting holes with the lug holes of
the top piece aligned with the plurality of mounting holes; and, a
blower housing bottom piece having a peripheral edge that extends
around the bottom piece, a plurality of mounting flanges that
project outwardly from the bottom piece peripheral edge with each
mounting flange having a flange hole, the bottom piece being
positioned on an opposite side of the annular wall from the top
piece and being dimensioned to be positioned on the device surface
with the flange holes aligned with the plurality of mounting
holes..].
.[.2. The blower of claim 1, further comprising: the blower housing
annular wall extending around the peripheral edge of the bottom
piece..].
.[.3. The blower of claim 1, further comprising: each lug of the
plurality of lugs being positioned opposite a mounting flange of
the plurality of mounting flanges on opposite sides of the annular
wall..].
.[.4. The blower of claim 1, further comprising: each lug hole
being positioned opposite a flange hole on opposite sides of the
annular wall..].
.[.5. The blower of claim 1, further comprising: the plurality of
lugs being spatially arranged around the top piece peripheral edge
and the plurality of mounting flanges being spatially arranged
around the bottom piece peripheral edge..].
6. .[.The blower of claim 1, further comprising:.]. .Iadd.A blower
for a climate control device having a surface with a plurality of
mounting holes arranged in a pattern around the surface for
mounting the blower to the surface of the device, the blower
comprising: a blower housing top piece having a peripheral edge
that extends around the top piece, a plurality of lugs that project
outwardly from the peripheral edge with each lug having a lug hole;
a blower housing annular wall having a volute shape with a
discharge pipe projecting from the annular wall, the annular wall
extending around the peripheral edge of the top piece and being
dimensioned to be positioned on the device surface inside the
pattern of the plurality of mounting holes with the lug holes of
the top piece aligned with the plurality of mounting holes; a
blower housing bottom piece having a peripheral edge that extends
around the bottom piece, a plurality of mounting flanges that
project outwardly from the bottom piece peripheral edge with each
mounting flange having a flange hole, the bottom piece being
positioned on an opposite side of the annular wall from the top
piece and being dimensioned to be positioned on the device with the
flange holes aligned with the plurality of mounting holes; a
plurality of fasteners, each fastener having a head and a shaft and
each fastener shaft having a cylindrical length that extends
through a lug hole, across the annular wall, and through a flange
hole with a spacing between the annular wall and the shaft being
substantially constant along a majority of the shaft length;
and,.Iaddend. a plurality of legs spatially arranged around the top
piece peripheral edge and the bottom piece peripheral edge, each
leg projecting outwardly from the top piece peripheral edge and the
bottom piece peripheral edge and each leg having an interior
surface that extends between a lug hole and a flange hole.
7. .[.The blower of claim 1, further comprising:.]. .Iadd.A blower
for a climate control device having a surface with a plurality of
mounting holes arranged in a pattern around the surface for
mounting the blower to the surface of the device, the blower
comprising: a blower housing top piece having a peripheral edge
that extends around the top piece, a plurality of lugs that project
outwardly from the peripheral edge with each lug having a lug hole;
a blower housing annular wall having a volute shape with a
discharge pipe projecting from the annular wall, the annular wall
extending around the peripheral edge of the top piece and being
dimensioned to be positioned on the device surface inside the
pattern of the plurality of mounting holes with the lug holes of
the top piece aligned with the plurality of mounting holes; a
blower housing bottom piece having a peripheral edge that extends
around the bottom piece, a plurality of mounting flanges that
project outwardly from the bottom piece peripheral edge with each
mounting flange having a flange hole, the bottom piece being
positioned on an opposite side of the annular wall from the top
piece and being dimensioned to be positioned on the device with the
flange holes aligned with the plurality of mounting holes; a
plurality of fasteners, each fastener having a head and a shaft and
each fastener shaft having a cylindrical length that extends
through a lug hole, across the annular wall, and through a flange
hole with a spacing between the annular wall and the shaft being
substantially constant along a majority of the shaft length; and, a
.Iaddend.plurality of legs spatially arranged around the top piece
peripheral edge and the bottom piece peripheral edge and extending
across the annular wall between a lug and a mounting flange, each
leg projecting outwardly from the top piece peripheral edge, the
bottom piece peripheral edge and the annular wall.
.[.8. The blower of claim 1, further comprising: each of the lug
holes and each of the flange holes having oblong shapes..].
.[.9. The blower of claim 1, further comprising: the top piece
having a shaft hole extending through the top piece and a plurality
of mounting fittings spatially arranged around the shaft hole to
enable attaching a motor to the top piece with a shaft of the motor
passing through the shaft hole..].
.[.10. The blower of claim 3, further comprising: each lug hole
having an oblong shape..].
.[.11. A blower for a climate control device having a surface for
mounting the blower to the device, the blower comprising: a blower
housing top piece having a peripheral edge that extends around the
top piece, a shaft hole extending through the top piece and a
plurality of mounting fittings spatially arranged around the shaft
hole for attaching a motor to the top piece with a shaft of the
motor passing through the shaft hole, a blower housing annular wall
having a volute shape with a discharge pipe projecting from the
annular wall, the annular wall extending around the peripheral edge
of the top piece; and, a plurality of legs spatially arranged
around the peripheral edge of the top piece and projecting
outwardly from the peripheral edge and outwardly from the annular
wall, the legs extending from the top piece peripheral edge across
the annular wall to support the top piece in a horizontal
orientation above the annular wall and the climate control device
surface when the blower is mounted on the device surface..].
.[.12. The blower of claim 11, further comprising: a motor mounted
on the top piece by the mounting fittings, the plurality of legs
supporting the motor in a vertical orientation on the top piece and
supporting the top piece in a horizontal orientation above the
annular wall and the climate control device surface when the blower
is mounted on the surface..].
.[.13. The blower of claim 11, further comprising: a plurality of
fasteners extending through the plurality of legs to mount the
blower to the climate control device surface..].
.[.14. The blower of claim 13, further comprising: each of the
plurality of fasteners has a driving end that seats against the top
piece..].
.[.15. The blower of claim 14, further comprising: each fastener
driving end extending horizontally over the annular wall..].
16. .[.The blower of claim 11, further comprising:.]. .Iadd.A
blower for a climate control device having a surface for mounting
the blower to the device, the blower comprising: a blower housing
top piece having a peripheral edge that extends around the top
piece, a shaft hole extending through the top piece and a plurality
of mounting fittings spatially arranged around the shaft hole for
attaching a motor to the top piece with a shaft of the motor
passing through the shaft hole, a blower housing annular wall
having a volute shape with a discharge pipe projecting from the
annular wall, the annular wall extending around the peripheral edge
of the top piece; a plurality of legs spatially arranged around the
peripheral edge of the top piece and projecting outwardly from the
peripheral edge and outwardly from the annular wall, the legs
extending from the top piece peripheral edge across the annular
wall to support the top piece in a position on an opposite side of
the annular wall from the climate control device surface when the
blower is mounted on the device surface; a plurality of fasteners
extending across the annular wall, each fastener having a shaft
with a driving end at one end of the shaft and a driven end at an
opposite end of the shaft, each fastener shaft having a length that
is positioned adjacent and substantially parallel to the annular
wall for a majority of the shaft length, and each fastener driving
end seating against the top piece; and, .Iaddend. a plurality of
lugs spatially arranged around the top piece peripheral edge
projecting outwardly from the peripheral edge, each lug has a lug
hole, and the plurality of legs extend downwardly from the
plurality of lugs.
17. .[.The blower of claim 11, further comprising:.]. .Iadd.A
blower for a climate control device having a surface for mounting
the blower to the device, the blower comprising: a blower housing
top piece having a peripheral edge that extends around the top
piece, a shaft hole extending through the top piece and a plurality
of mounting fittings spatially arranged around the shaft hole for
attaching a motor to the top piece with a shaft of the motor
passing through the shaft hole, a blower housing annular wall
having a volute shape with a discharge pipe projecting from the
annular wall, the annular wall extending around the peripheral edge
of the top piece; a plurality of legs spatially arranged around the
peripheral edge of the top piece and projecting outwardly from the
peripheral edge and outwardly from the annular wall, the legs
extending from the top piece peripheral edge across the annular
wall to support the top piece in a position on an opposite side of
the annular wall from the climate control device surface when the
blower is mounted on the device surface; a plurality of fasteners
extending across the annular wall, each fastener having a shaft
with a driving end at one end of the shaft and a driven end at an
opposite end of the shaft, each fastener shaft having a length that
is positioned adjacent and substantially parallel to the annular
wall for a majority of the shaft length, and each fastener driving
end seating against the top piece; and, .Iaddend. a blower housing
bottom piece having a peripheral edge that extends around the
bottom piece, a plurality of mounting flanges that project
outwardly from the bottom piece peripheral edge with each mounting
flange being positioned to be engaged by a leg of the plurality of
legs when the blower housing is mounted on the climate control
device surface.
18. The blower of claim 17, further comprising: each mounting
flange having a flange hole.
19. The blower of claim 17, further comprising: blower housing
annular wall extends around the peripheral edge of the bottom
piece.
.[.20. A blower for a climate control device having a surface with
a plurality of mounting holes arranged in a pattern on the surface
for mounting the blower to the surface of the device, the blower
comprising: a blower housing annular wall having a volute shape
with a discharge pipe projecting from the annular wall, the annular
wall being dimensioned to be positioned on the device surface
inside the pattern of the plurality of mounting holes; a blower
housing top piece extending across the annular wall, the blower
housing top piece having a plurality of lug holes spatially
arranged outside the annular wall and in a pattern that aligns each
lug hole with a mounting hole on the device surface when mounting
the blower to the device surface, each of the lug holes having an
oblong shape; and, a blower housing bottom piece extending across
the annular wall on an opposite side of the annular wall from the
blower housing top piece, the bottom piece having a plurality of
flange holes spatially arranged outside the annular wall and in a
pattern that aligns each flange hole with a mounting hole on the
device surface when mounting the blower to the device surface, and
each of the flange holes having an oblong shape..].
.[.21. The blower of claim 20, further comprising: the top piece
having a peripheral edge that follows the volute shape of the
annular wall and the bottom piece having a peripheral edge that
follows the volute shape of the annular wall..].
.[.22. The blower of claim 20, further comprising: the top piece
having a peripheral edge and a plurality of lugs projecting
outwardly from the peripheral edge with the plurality of lug holes
being in the plurality of lugs; and the bottom piece having a
peripheral edge and a plurality of mounting flanges projecting
outwardly from the peripheral edge with the plurality of flange
holes being in the mounting flanges..].
23. .[.The blower of claim 20, further comprising:.]. .Iadd.A
blower for a climate control device having a surface with a
plurality of mounting holes arranged in a pattern on the surface
for mounting the blower to the surface of the device, the blower
comprising: a blower housing annular wall having a volute shape
with a discharge pipe projecting from the annular wall, the annular
wall being dimensioned to be positioned on the device surface
inside the pattern of the plurality of mounting holes; a blower
housing top piece extending across the annular wall, the blower
housing top piece having a plurality of lug holes spatially
arranged outside the annular wall and in a pattern that aligns each
lug hole with a mounting hole on the device surface when mounting
the blower to the device surface, each of the lug holes having an
oblong shape; a blower housing bottom piece extending across the
annular wall on an opposite side of the annular wall from the
blower housing top piece, the bottom piece having a plurality of
flange holes spatially arranged outside the annular wall and in a
pattern that aligns each flange hole with a mounting hole on the
device surface when mounting the blower to the device surface, and
each of the flange holes having an oblong shape; a plurality of
fasteners, each fastener having a head and a shaft and each
fastener shaft having a cylindrical length that extends through a
lug hole, across the annular wall, and through a flange hole with a
spacing between the annular wall and the shaft being substantially
constant along a majority of the shaft length; and, .Iaddend. the
top piece having a peripheral edge; the bottom piece having a
peripheral edge; and, a plurality of legs that project outwardly
from the top piece peripheral edge and the bottom piece peripheral
edge and extend between the plurality of lug holes and the
plurality of flange holes.
.Iadd.24. A blower housing comprising: a top piece having an outer
peripheral edge; an annular wall; and, a bottom piece having an
outer peripheral border, the bottom piece being connectable with
the top piece with the annular wall between the bottom piece and
top piece, the bottom piece having a plurality of mounting flanges
that project outwardly from the bottom piece outer peripheral
border and each of the mounting flanges has a flange hole with an
inner edge configured to position a fastener flush along at least a
majority of the annular wall; the top piece has a plurality of lugs
that project outwardly from the top piece outer peripheral edge and
each lug has a leg that extends across the annular wall and
connects with a mounting flange of the bottom piece; and, each leg
has an arcuate interior surface that opposes the annular
wall..Iaddend.
.Iadd.25. The blower housing of claim 24, wherein: each lug has a
lug hole that is aligned with a flange hole enabling fasteners to
be positioned through the lug holes, between the annular wall and
the arcuate interior surfaces of the legs and through the flange
holes..Iaddend.
.Iadd.26. A blower for a climate control device having a surface
with a plurality of mounting holes arranged in a pattern on the
surface for mounting the blower to the surface of the device, the
blower comprising: a blower housing annular wall having a volute
shape with a discharge pipe projecting from the annular wall, the
annular wall being dimensioned to be positioned on the device
surface inside the pattern of the plurality of mounting holes; a
blower housing top piece extending across the annular wall, the
blower housing top piece having a plurality of lug holes spatially
arranged outside the annular wall and in a pattern that aligns each
lug hole with a mounting hole on the device surface when mounting
the blower to the device surface, each of the lug holes having an
oblong shape; a blower housing bottom piece extending across the
annular wall on an opposite side of the annular wall from the
blower housing top piece, the bottom piece having a plurality of
flange holes spatially arranged outside the annular wall and in a
pattern that aligns each flange hole with a mounting hole on the
device surface when mounting the blower to the device surface, and
each of the flange holes having an oblong shape; a plurality of
fasteners, each fastener having a head and a shaft and each
fastener shaft having a cylindrical length that extends through a
lug hole, across the annular wall, and through a flange hole with a
spacing between the annular wall and the shaft being substantially
constant along a majority of the shaft length; and, each fastener
head having a width that is larger than a width of the fastener
shaft, and each fastener head being positioned in engagement with a
lug outside the lug hole..Iaddend.
.Iadd.27. The blower of claim 26, further comprising: each fastener
head overlapping an end of the annular wall..Iaddend.
Description
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to blowers used on high efficiency
(e.g. 90% or higher efficiency) furnaces for drawing air from
outside the home into the furnace to support combustion and for
expelling the combustion exhaust products outside the home. More
particularly, the invention relates to a construction of a blower
housing that maximizes the interior space available for the blower
impeller.
(2) Description of the Related Art
Combustion blowers for high efficiency furnaces are common in the
art. These blowers are used to draw air for combustion from outside
the home. Generally, these blowers are located downstream of a
combustion chamber or combustion tubes in the furnace, depending
upon the style of furnace, into which the combustion air is drawn,
mixed with fuel, and ignited to generate heat for the furnace. The
exhaust gases are drawn into the suction side of the blower and
discharged from the blower through an exhaust pipe that vents to
outside atmosphere.
Although the mounting arrangement and available space inside the
blower is similar between one furnace model and the next, each
model of furnace typically is designed to use a specific type and
size blower. Among other general specifications set by the furnace
manufacturer, the blower must meet requirements for dimensional
size, mounting arrangements, and air moving capacity. In
particular, the size of the blower housing must fit within a given
space which then in turn determines the location of mounting holes
in the furnace bonnet. Thus, these dimensional size requirements
limit the air moving capacity of a blower because the impeller size
must be chosen to fit and operate efficiently within the given size
housing.
In order to increase the air moving capacity of the blower given
the fixed size for the blower housing and the impeller, the
designer may choose to increase the speed of the impeller. This in
turn requires that the blower be operated with a higher speed
motor. This option has significant drawbacks, including increased
cost to buy, to operate, and increased noise. The speed of the
motor and the speed of the impeller must be closely matched to
maximize efficiency of the impeller. This requires additional
engineering considerations in designing the impeller to operate
efficiently at increased speeds. Efficient high speed motors are
generally more expensive and tends to increase the cost of the
blower. A blower with a higher speed motor also tends to produce
more noise and vibration. The higher speed motor also has greater
electrical demands. High speed blower motors tend to operate at
higher temperatures and generate more heat than lower speed motors.
Since the motor is in close proximity to hot exhaust gases in the
blower, higher speed motors may require auxiliary cooling systems
such as a shaft mounted fan, or a larger bonnet interior to avoid
heat buildup. Auxiliary cooling systems lower motor efficiency, and
the higher operating temperatures tend to decrease the life cycle
of the blower motor.
FIG. 1 shows a blower 20 of the prior art arranged on a blower
mounting surface 21 of a furnace 22. The blower 20 includes a
blower motor (not shown) and a blower housing 24. In FIG. 1, the
blower motor has been removed from its center mount 26 on top of
the blower housing 24 to show greater detail of the blower housing
24. The blower housing 24 has a side wall 28 extending between a
top piece 30 and a bottom piece 32. The top piece 30 is molded with
the center mount recess 26 to receive the blower motor (not shown).
The side wall 28, top piece 30, and bottom piece 32 form a volute
34 for the blower housing 24. When the blower 20 is energized, an
impeller (not shown), operably connected to a shaft of the blower
motor (not shown), rotates in the volute 34 to draw exhaust gases
through an inlet hole 35 in the center of the bottom piece 32 and
to compress gases in the volute 34. The pressurized exhaust gases
are directed into a discharge pipe 36 that extends outward and away
from the blower 20 and the furnace 22.
As shown in FIG. 1, mounting feet 38 for attaching the blower 20 to
the blower mounting surface 21 of the furnace 22 are provided on
the side wall 28 of the blower housing 24. In order to secure the
blower housing 24 to the furnace, mechanical fasteners 40 are used.
The typical mechanical fastener 40 used to secure the blower 20 to
the furnace 22 has a screw head driving end 42 and an opposite
driven end 43 spaced from the driving end 42 by a shaft 44. The
driving end 42 is larger than the shaft 44 such that it engages a
sealing surface 46 on the mounting foot 38 and holds the blower 20
to the furnace. The seating surface 46 of the mounting foot 38 is
sized to allow clearance between the driving end 42 of the fastener
40 and the side wall 28 of the blower housing 24.
In the construction of older blower housings, a cut-out in the side
wall of the blower housing is sometimes provided adjacent the
mounting feet for clearance of the driving end of the mechanical
fastener. A sponge foam rubber or rubber type sealing insert is
then used once the fastener is installed to completely seal the
housing along the narrow spacing adjacent the driving end of the
fastener. These inserts and gaskets are problematic in that they
tend to leak over time and represent the weak link in exhaust
system integrity. Additionally, some blower housing constructions
require the use of gasket material to build up the axial height of
the bottom piece in the area of the mounting foot when the blower
is installed on the furnace. This gasket material seals the blower
housing in the area of the mechanical fastener and prevents the
mounting foot from heeling over when the mechanical fastener is
tightened and the blower housing is attached to the furnace.
What is needed to overcome the disadvantages of the prior art is a
blower housing which has a maximized interior space to permit the
use of the largest capacity impeller practicable while meeting the
size restrictions set by the mounting holes located in the furnace
by the manufacturer. The blower housing having the largest
practicable capacity impeller would meet the manufacturer's
requirements for air moving capacity with a lower speed motor. Such
a blower would meet furnace manufacturers' specifications for air
moving capacity with decreased noise and vibration, and cost for
the blower. Additionally, such a blower would eliminate the need
for sealing inserts or gasket materials at the mounting locations
for the blower housing.
SUMMARY OF THE INVENTION
In order to overcome the disadvantages of the prior art, the blower
of the present invention provides an increased interior spacing
while maintaining fixed exterior dimensions including especially
the mounting hole locations. By having a larger interior for
containing a larger impeller than in the prior art design, the
blower of the present invention is capable of generating a higher
air moving capacity with a decreased operating speed, cost, and
lower noise and vibration levels. The blower of present invention
also improves the containment of exhaust gases in the blower
housing by improving the integrity of the seal around the housing
against the furnace bonnet.
The blower of the present invention includes a blower housing and a
blower motor. The blower housing has a top piece, a side wall, and
a bottom piece that detachably engages the top piece to enclose the
blower housing. The top piece includes an annular lower support
portion for supporting the blower motor and an annular upper
portion extending above and around the lower portion. The upper
portion of the top piece of the blower housing has an outer
peripheral edge and at least one lug extending outwardly beyond its
outer peripheral edge. The bottom piece of the blower housing has a
flange extending beyond its periphery that aligns with the lug of
the top piece when the blower housing is assembled. The flange
interlocks with the lug to detachably engage the top piece to the
bottom piece. The top piece, side wall and bottom piece thus form a
volute for the blower housing when assembled.
The lug on the top piece has a lug hole to receive a mechanical
fastener such as a threaded bolt or screw. The flange on the bottom
piece preferably has a flange hole that receives the mechanical
fastener therethrough when the mechanical fastener joins the top
piece to the blower mounting surface of the furnace. The mechanical
fastener preferably attaches the blower housing to the furnace such
that the blower housing is positioned between a blower motor and
exterior mounting surface of the furnace. Thus, by locating the
mechanical fastener with its head above the top piece, it may be
driven tightly against the lug at the top of the blower and space
need not be provided for the head of the mechanical fastener to be
driven tightly against a blower housing surface which itself is
located within the envelope of the impeller space.
In other words, in the prior art construction as seen in FIG. 1, a
seating surface 46 is provided against which the driving end must
be snugged to adequately secure the blower to the furnace. This
requires a shoulder of a minimum width between the lug hole and the
blower housing sidewall, which shoulder width (along with any
clearance between the mounting hole sidewall and the shoulder)
represents wasted space as the location of the blower housing
sidewall is what limits the diameter of the impeller. With the
present invention, the blower housing sidewall may be immediately
adjacent the shaft 44 as the driving end is snugged against a
surface located above the blower housing sidewall. Thus, little
clearance need be provided between the shaft as the screwdriver or
other tool used to secure the mechanical fastener has complete and
unimpeded access to the driving end as it remains above the blower
housing.
In another aspect of the present invention, the blower housing is
provided with an improved seal between the top and bottom pieces.
Preferably, the blower housing comprises a bottom piece having a
disk shaped bottom portion with an outer perimeter border and an
upstanding annular wall extending outward from the bottom disk
around the outer perimeter border. The upstanding annular wall has
an interior surface that forms a portion of the volute for the
blower housing. The upstanding wall has an annular end axially
opposite the bottom disk portion that extends between the exterior
and interior surfaces of the upstanding wall. The annular end has
an annular lip axially spaced from the annular end.
The top piece fits over the bottom piece to enclose the volute and
form a casing for the blower. The top piece has a lower portion
recessed into the top piece and extending into the casing. This
lower portion receives the blower motor. The top piece also has an
upper portion which extends around and above the lower portion. The
upper portion has a primary groove and an outer peripheral edge
surrounding the primary groove. The primary groove has an annular
outer side wall and an annular inner side wall spaced apart by an
annular groove wall. The groove wall has a secondary groove
intermediate the coterminous edges of the groove wall and inner and
outer side walls. The inner side wall of the primary groove abuts
the interior surface of the upstanding wall of the bottom piece and
the annular lip of the bottom piece is received in the secondary
groove when the casing is assembled.
The inner side wall of the primary groove preferably has an annular
rib extending outwardly from the side wall into the primary groove.
The interior surface of the upstanding annular wall preferably has
an annular notch on its interior surface. In this arrangement, as
the annular notch receives the annular rib in the primary groove,
the pieces tend to "snap" together as the bottom piece is fully
assembly with the top piece. This construction thus provides a
positive indicator of sealing between the top and bottom pieces
when the blower housing is assembled.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
Further objects and features of the invention are revealed in the
following detailed description of the preferred embodiment of the
invention and in the drawings wherein:
FIG. 1 is an exploded, perspective view of a blower of the prior
art;
FIG. 2 is a side view of a blower of the present invention
installed on a mounting structure of the furnace;
FIG. 3 is a perspective view of a blower housing of the blower of
FIG. 2;
FIG. 4 is a top, perspective view of a top piece of the blower
housing of FIG. 3;
FIG. 5 is a bottom, perspective view of the top piece of FIG.
4;
FIG. 6 is a top, perspective view of a bottom piece of the blower
housing of FIG. 3;
FIG. 7 is a bottom, perspective view of the bottom piece of FIG.
6;
FIG. 8 is a cross-sectional view of the top piece installed with
the bottom piece to form the blower housing of FIG. 3; and
FIG. 9 is a cross-sectional view of the top piece installed with
the bottom piece to form the blower housing of FIG. 3.
Corresponding reference numerals indicate corresponding parts
throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2 shows the blower of the present invention installed in a
furnace. The blower 50 includes a blower motor 52 and a blower
housing 54. The blower housing 54 has an annular upstanding wall 56
extending between a top piece 58 and bottom piece 60. The bottom
piece 60 is mounted on a blower mounting surface 21 in the furnace
22, or the furnace bonnet, using mechanical fasteners 40. The
driving end 42 of each of the fasteners 40 seats against the top
most portion of top piece 58 and the driven end 43 is installed in
the blower mounting surface 21 on the furnace 22. In the
arrangement shown in FIG. 2, the bottom piece 60 is preferably held
in position between the top piece 58 and the blower mounting
surface 21 by compression from the mechanical fasteners 40.
As shown in FIG. 2, the blower 50 is mounted on a blower mounting
surface 21 on the furnace 22 where the blower housing 54 is
positioned to allow the impeller (not shown) to draw exhaust gases
directly from the combustion chamber or combustion tubes (not
shown) into the blower housing 54. A discharge pipe 61 is coupled
to an exhaust pipe 62 using a gasket 64 to vent the exhaust gases
to atmosphere.
FIG. 3 shows a perspective view of the blower housing 54 with top
piece assembled on the bottom piece 60. The top piece 58 covers
over the bottom piece 60 to tightly enclose the blower housing 54
and prevent exhaust gases from leaking from the blower housing 54
during operation. The top piece 58 has a lower portion 66 that is
received into the top piece 58 and extends into the blower housing
casing 54. The diameter of the recessed lower portion 66 is sized
to accommodate the blower motor 52. The lower portion 66 has
mounting fittings 68 for securing the blower motor to the top piece
58. The lower portion 66 may also have screw fittings 70 for
securing the motor to the top piece 58. At the center of the lower
portion 66, a through hole 72 is provided to allow a shaft (not
shown) from the blower motor to pass into the interior of the
blower housing 54 to be coupled with the impeller (not shown). The
top piece 58 has an upper portion 74 which extends around and above
the lower portion 66 and includes a seating surface 76 for the
mechanical fasteners 40.
FIGS. 4 and 5 provide greater detail of the top piece 58. The upper
portion 74 of the top piece 58 has an outer peripheral edge 78 and
lugs 80 extending radially outward beyond the outer peripheral edge
78. The lugs 80 preferably have arcuate lug holes 82 formed therein
to allow adjustable positioning of the blower housing 54 on the
blower mounting surface 21 of the furnace 22 when the blower 50 is
installed on the furnace 22. Preferably, each of the lugs 80 has a
depending leg 84 extending downward and away from the outer
peripheral edge 78 of the top piece 58. Each leg 84 preferably has
an exterior surface 86 and an arcuate interior surface 88 which
gives each leg 84 a generally concave aspect when it is installed
on the blower housing 54. The arcuate interior surface 88 of the
depending leg 84 preferably has a circumferential guide portion 90
that conforms to the upstanding annular wall 56 on the bottom piece
60. The circumferential guide portion 90 on the depending leg 84
supports and aligns the top piece 58 with the bottom piece 60
during operation. The depending leg 84 bears some of the weight of
the blower motor when the blower 50 is installed on the blower
mounting surface 21 of the furnace 22.
As shown in FIG. 5, an annular locating groove 92 is provided
around the upper portion 74 radially inward of the outer peripheral
edge 78. The annular locating groove 92 is positioned a sufficient
distance away from the outer peripheral edge 78, lug hole 82, and
depending leg 84 so as not to interfere with the seal between the
top piece 58 and bottom piece 60 when the blower housing 54 is
assembled. Greater detail of the annular locating groove 92 and
seal between the top and bottom pieces 58,60 will be discussed
later with reference to FIG. 8.
FIGS. 6 and 7 provide detail of the bottom piece 60 of the blower
housing 54. The bottom piece 60 has a bottom disk portion 94 with a
center inlet hole 95 that allows the blower 50 to draw exhaust
gases into the housing 54 during blower operation. The bottom disk
portion 94 has an outer perimeter border 96 and the upstanding
annular wall 56 extends outward and away from the outer perimeter
border 96. The underside of the bottom disk portion 94 of the
blower housing 54 is generally flat so that it may be mounted flush
against the blower mounting surface 21 of the furnace 22. The
upstanding annular wall 56 has an interior surface 98 which defines
a portion of a volute 100 of the blower housing 54 and an exterior
surface 102 that surrounds the interior surface 98. The discharge
pipe 61 extends outward and away from the annular wall 56 and
communicates with the volute 100 to direct pressurized exhaust
gases from the blower housing 54. The discharge pipe 61 may have a
boss end 105 to allow connection to the exhaust pipe 62, as
required. Preferably, the bottom disk portion 94, the upstanding
wall 56, and the discharge pipe 61 are formed monolithically.
The bottom piece 58 is provided with a plurality of mounting
flanges 106 circumferentially spaced around the outer perimeter
border 96 of the bottom disk portion 94. Each of the mounting
flanges 106 extends radially outward from the outer perimeter
border 96 and has a flange hole 108 therethrough. Each of the
mounting flanges 106 preferably aligns with a corresponding lug 80
on the top piece 58. The alignment of the lugs 80 and flanges 106
may be such that the top piece 58 and bottom piece 60 are assembled
in only one orientation. Similar to the lug hole 82, the flange
hole 108 is also preferably arcuate to allow minor adjustment of
the blower 50 when the blower 50 is mounted on the blower mounting
surface 21 of the furnace 22. To maximize the diameter of the
upstanding annular wall 56, an inner edge 110 of the flange hole
108 may be formed flush with the exterior surface 102 of the
upstanding annular wall 56.
Preferably, the flange hole 108 is also formed to receive the
depending leg 84 of the top piece 58 when the blower 50 is
assembled. As shown in FIG. 9, the flange hole 108 preferably has a
step recess 112 which is shaped to receive the depending leg 84
from the lug 80 of the top piece 58 and a through hole 113. The
through hole 113 allows the mechanical fastener to be directed from
the lug 80 and lug hole 82 on the top piece 58 to the blower
mounting surface 21 on the furnace 22 when the blower 50 is secured
to the blower mounting surface 21 on the furnace 22. The step
recess 112 positively aligns the depending leg 84 and captures a
bottom portion of the circumferential guide portion 90 of the
depending leg 84 so that the top piece 58 and bottom piece 60 are
positively engaged both during assembly and operation of the blower
50. It is preferred that the bottom piece 60 be held in position by
the compressive forces exerted by the mechanical fastener 40 on the
top piece 58. The step recess 112 bears some of this compressive
force and stabilizes the position of the bottom piece 60 adjacent
the blower mounting surface 21 of the furnace 22.
Details of the attachment between the top and bottom pieces are
best shown in FIG. 8. The upstanding annular wall 56 of the bottom
piece 60 has an upper section 114 that cooperates with the annular
groove 92 in the upper portion 74 of the top piece 58. The upper
section 114 includes an annular end 116 that extends between the
interior and exterior surfaces 98,102 of the upstanding wall 56.
The annular end 116 has a lip 118 extending axially outward from
the bottom disk portion 94 intermediate the coterminous edges of
the annular end 116 and the interior and exterior surfaces 98,102
of the upstanding annular wall 56. Preferably, the annular lip 118
has a generally triangular shaped cross section to act as a guide
during assembly as well as an overlapping fit between the top and
bottom pieces 58,60. The upper section 114 also importantly
includes an annular notch 120 extending around the interior surface
98 of the upstanding wall 56.
The annular groove 92 formed in the upper portion 74 of the top
piece 58 includes a primary groove 122 and a secondary groove 124.
The primary groove 122 includes an annular inner side wall 126 and
an annular outer side wall 128 spaced apart from the annular inner
side wall 126 by an annular groove wall 130. When the top piece 58
is installed on the bottom piece 60, the annular inner side wall
126 abuts the interior surface 98 of the upstanding annular wall
56, and the annular outer side wall 128 faces the exterior surface
102 of the upstanding annular wall 56. The annular outer side wall
128 may be formed with a lead-in taper 132 to allow the top and
bottom pieces 58,60 to more easily fit together.
The primary groove 122 also includes an annular rib 134 axially
spaced below the annular groove wall 130. The annular rib 134
cooperates with the annular notch 120 in the upstanding annular
wall 56 of the bottom piece 58 to form a first sealing area 136 for
the blower housing 54. When the top piece 58 is fully installed on
the bottom piece 60, the top piece 58 will snap fit onto the bottom
piece 60 as the annular rib 134 slides across the interior surface
98 of the upstanding annular wall 56 and into the annular notch
120. The rib 134 and notch 120 provide a positive lock indication
for a blower assembly operator when assembling the blower housing
54.
The secondary groove 124 in the annular groove 92 on the upper
portion 74 of the top piece 58 is formed internal to primary groove
122. The secondary groove 124 is formed intermediate the
coterminous edges of the annular groove wall 130 and inner and
outer side walls 126,128. The secondary groove 124 has a generally
triangular shaped cross section that matches the geometry of the
annular lip 118 on the upstanding wall 56 of the bottom piece 60.
The secondary groove 124 provides a secondary sealing area 138 for
the blower housing.
In assembling the blower housing 50 into the arrangement shown in
FIG. 3, the top piece 58 may be installed with the bottom piece 60
to create the blower housing 54 of the present invention. The upper
section 114 of the annular wall 56 of the bottom piece 60 may be
inserted into the annular groove 92 on the underside of the top
piece 58 and positively locked in place to seal the blower housing
54.
The depending legs 84 of the lug 80 of the top piece 58 may be
inserted into the step recess 112 formed in the flange hole 108
such that the circumferential guide portion 90 of the interior
arcuate surface 88 of the depending lug 84 mounts flush against the
exterior surface 102 of the upstanding annular wall 56 of the
bottom piece 60 and a bottom portion of the leg 84 is nested within
the recess 112 of the flange hole 108. Preferably, the lengths of
the depending legs 84 are sized such that when the upper section
114 of the annular wall 56 is fully inserted into the annular
groove 92 in the top piece 58, the leg 84 is captured by the flange
hole 108. The lugs 80 and matching flanges 106 may have irregular
angular placement along each of the respective top and bottom
pieces 58,60 to provide a keying assembly for the blower housing 54
such that the top and bottom pieces 58,60 may be assembled in only
one orientation.
Each of the top and bottom pieces 58,60 may be formed from
materials that are capable of withstanding relatively high
temperatures from the exhaust gases being expelled from the blower
housing 54. The blower housing 54 may be made from a polypropylene
or polyvinyl chloride (PVC) type plastic, although other materials
capable of withstanding the heat from the exhaust gases may also be
used. The material used must be sufficiently resilient to allow the
top piece 58 and bottom piece 60 to flex during installation so
that the top piece 58 and bottom piece 60 may properly form the
primary and secondary seals 136,138 in the blower housing 54.
By locating the lugs 80 on the upper portion 74 of the blower
housing 54, the diameter of the upstanding annular wall 56 can be
increased. By moving the driving end 42 of the mechanical fastener
40 above the lug 80 on the top piece 58, the clearance between the
screw head driving end 42 and the upstanding annular wall 56 of the
blower housing 50, as well as any clearance between the shaft and
the opening through which it extends can be eliminated. The
mechanical fastener 40 used to secure the blower housing to the
blower mounting surface of the furnace may run directly down the
exterior surface 102 of the upstanding annular wall 56 because
there is sufficient clearance on the upper portion 74 of the top
piece 58 for the screw head driving end 42 of the mechanical
fastener 40. Furthermore, there may also be a savings in assembly
time as the driving head is much more readily accessible with the
fastening tool making it easier to apply the tool to the driving
head.
As the top piece 58 snap fits with the bottom piece 60 to create a
sealed unit, gasket materials and other sealing inserts commonly
used in the prior art are no longer needed. By constructing the
bottom piece 60 with a flat bottom disk and an upstanding annular
wall 56 extending from the outer perimeter border 96 of the bottom
disk portion 94, and a top piece with the annular grove 92, the
locations for the seals 136,138 between the top piece 58 and bottom
piece 60 are moved to a position on the blower housing 54 where use
of mechanical fasteners 40 does not interfere with the integrity of
the seals 136,138. By locating the lugs 80 on the outer peripheral
edge 78 of the upper portion 74 of the top piece 58, the upper
portion 74 of the top piece 58 may flex inward such that the
normally tapered outer side wall 128 of the primary groove 122
contacts the exterior surface 102 of the upstanding wall 56. Thus,
the combination of the primary seal 136 and internal secondary seal
138 provides improved sealing characteristics for the blower
housing 54 not found in the prior art.
Although the description of the blower housing presented herein
refers to a primary and secondary seals formed on respective
portions of the top and bottom pieces, it should be noted that the
location and combination of the components comprising the primary
and secondary seals may be reversed and positioned on the other of
the top and bottom pieces of the blower housing.
Various other changes to the preferred embodiment of this invention
described above may be envisioned by those of ordinary skill in the
art. However, those changes and modifications should be considered
as part of the invention which is limited only by the scope of the
claims appended hereto and their legal equivalents.
* * * * *