Note: Descriptions are shown in the official language in which they were submitted.
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SECONDARY LINT TRAP FOR RESIDENTIAL LAUNDRY DRYER
Technical Field
[0001] This disclosure concerns a secondary lint trap for use with
laundry dryers in residential building suites.
Back rg ound
[0002] Modern multiple-suite high-rise residential buildings have
ventilation systems with floor or ceiling-embedded vent ducts. Each suite has
one or more vent ducts. Exhaust conduits are used to connect exhaust air
sources within the suite to one of the vent ducts. Bathroom fans, range hood
fans and laundry dryers are typical exhaust air sources. For example, one
exhaust conduit may be connected between the exhaust outlet of a bathroom
fan and a vent duct, a second exhaust conduit may be connected between the
exhaust outlet of a range hood fan and a vent duct, a third conduit may be
connected between the exhaust outlet of a laundry dryer and a vent duct, etc.
Exhaust air is expelled into the conduits and exhausted from the building
through the vent ducts.
[0003] Conventional residential laundry dryers have built-in primary lint
traps. However, a dryer's damp, warm exhaust air may contain a substantial
amount of excess lint which is not trapped by the dryer's primary lint trap. A
secondary lint trap can be coupled between the dryer's exhaust outlet and the
building's vent duct to reduce the accumulation of lint in the vent duct.
[0004] A stackable laundry washer/dryer unit 10 (Figure 1) incorporat-
ing a dryer 12 stacked atop a washer 14 is often used to conserve space in a
high-rise building suite. Figure 1 depicts two alternative prior art configura-
tions for coupling dryer 12 to one or the other of prior art secondary lint
traps
16A, 16B. As shown to the right in Figure 1, dryer 12's exhaust outlet 18
can be coupled through conduit 20A, 90 elbow 22A and conduit 24A to the
inlet 26A of prior art secondary lint trap 16A. Secondary lint trap 16A's
outlet 28A is coupled through conduit 30A and 90 elbow 32A to ceiling-
embedded vent duct 34A. Alternatively, as shown to the left in Figure 1,
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dryer 12's exhaust outlet 18 can be coupled through conduit 20B, 90 elbow
22B, conduit 21B, 90 elbow 23B and conduit 24B to the inlet 26B of prior
art secondary lint trap 16B. Secondary lint trap 16B's outlet 28B is coupled
through conduit 30B and 90 elbow 32B to ceiling-embedded vent duct 34B.
[0005] It is generally recommended that no more than two 90 elbows
and no more than 15 feet of conduit be used to connect a laundry dryer's
exhaust outlet to a building-embedded vent duct. Otherwise, air pressure in
the exhaust conduit(s) and vent duct is reduced, resulting in inefficient
operation of the dryer and potentially necessitating installation of an inline
fan
(not shown) to increase air pressure in the exhaust conduit(s) and vent duct.
The prior art configuration shown to the right in Figure 1 is somewhat
preferable to the configuration on the left, because the configuration on the
right has only two 90 elbows 22A, 32A whereas the configuration on the left
has three 90 elbows 22B, 23B, 32B. The configuration on the right is also
preferable if the combined length of conduits 20A, 24A and 30A is less than
the combined length of conduits 20B, 21B, 24B and 30B; particularly if the
combined length of conduits 20B, 21B, 24B and 30B exceeds 15 feet.
[0006] It is not always possible to adopt a 2-elbow configuration like
that shown to the right in Figure 1, nor is it always possible to adopt a
configuration requiring no more than 15 feet of conduit to connect a dryer's
exhaust outlet to a suite's built-in vent duct. This is problematic because if
moisture-laden air is not efficiently exhausted, moisture may accumulate
inside the elbows, exhaust conduit(s), vent duct, etc. potentially causing
water damage. Moreover, if a prior art secondary lint trap is mounted in a
location which is difficult to reach, the suite's occupant(s) may be unable or
may be disinclined to remove accumulated lint from the secondary lint trap
with sufficient frequency. Lint may accordingly accumulate in the secondary
lint trap to a point which further reduces the dryer's efficiency. In an
extreme case, accumulated lint can pose a fire hazard.
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[0007] The foregoing examples of the related art and limitations related
thereto are intended to be illustrative and not exclusive. Other limitations
of
the related art will become apparent to those of skill in the art upon a
reading
of the specification and a study of the drawings.
Brief Description of Drawings
[0008] Exemplary embodiments are illustrated in referenced figures of
the drawings. It is intended that the embodiments and figures disclosed
herein are to be considered illustrative rather than restrictive.
[0009] Figure 1 is an isometric illustration depicting two alternative
prior art configurations for connecting a laundry dryer through a prior art
secondary lint trap to a building-embedded vent duct.
[0010] Figure 2 is an isometric illustration depicting connection of a
laundry dryer to a building-embedded vent duct through an improved second-
ary lint trap.
[0011] Figure 3 is an enlarged isometric illustration of the Figure 2
secondary lint trap.
[0012] Figure 4 is an exploded isometric illustration of the Figure 3
secondary lint trap.
Description
[0013] Throughout the following description specific details are set forth
in order to provide a more thorough understanding to persons skilled in the
art. However, well known elements may not have been shown or described
in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the
description and drawings are to be regarded in an illustrative, rather than a
restrictive, sense.
[0014] Figure 2 depicts a stackable laundry washer/dryer unit 10
incorporating dryer 12 and washer 14 as described above in relation to Figure
1. Dryer 12's exhaust outlet 18 is coupled through 90 elbow 40 and conduit
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42 to the inlet collar 44 of secondary lint trap 46. Secondary lint trap 46's
outlet collar 48 is coupled through conduit 50 and 90 elbow 52 to ceiling-
embedded vent duct 54.
[0015] As best seen in Figures 3 and 4, secondary lint trap 46 includes
an elongate housing 56 which slidably receives a flat, elongate removable
tray 58 through frontal opening 60. Housing 56 may be formed by fastening
the side and rear edges 62, 64, 66 of a channel-shaped, sheet metal top part
68 to the corresponding side and rear edges 72, 74, 76 of a flat, sheet metal
bottom part 78. Top part 68 can be fastened to bottom part 78 by button-
locking top part 68's side and rear edges 62, 64, 66 to bottom part 78's side
and rear edges 72, 74, 76 respectively.
[0016] Inlet collar 44's flanged rim 80 is circumferentially fastened
around bottom part 78's downward-facing inlet aperture 82 so that collar 44
protrudes downwardly from the bottom side of housing 56's bottom part 78.
Inlet collar 44 and rim 80 are formed of sheet metal. Rim 80 may be welded
around inlet aperture 82.
[0017] Outlet collar 48's flanged rim 84 is circumferentially fastened
around top part 68's upward-facing outlet aperture 86 so that collar 48
protrudes upwardly from the top side of housing 56's top part 68. Outlet
collar 48 and its rim 84 are formed of sheet metal. Rim 84 may be welded
around outlet aperture 86.
[0018] Housing 56 is mounted atop dryer 12 such that inlet and outlet
collars 44, 48 extend rearwardly of dryer 12's rear wall 88. Such rearward
extension facilitates coupling of dryer 12's exhaust outlet 18 (which
protrudes
horizontally and rearwardly from dryer 12's rear wall 88) to inlet collar 44
through one 90 elbow 40 having an upward-facing outlet aligned with inlet
collar 44 via one short, substantially straight, elbowless conduit 42. Such
rearward extension also facilitates coupling of vent duct 54 to outlet collar
48
through one 90 elbow 52 having a downward-facing outlet aligned with
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outlet collar 48 via another short, substantially straight, elbowless conduit
50.
Double-sided foam tape can be used to mount housing 56 atop dryer 12.
[0019] Tray 58 is sized and shaped for snug-fit, slidably removable
insertion through housing 56's frontal opening 60. An aperture 92 is formed
near the rearward end 94 of tray 58. Aperture 92 is aligned between aper-
tures 82, 86 which are aligned with one another when top and bottom parts
68, 78 are assembled to form housing 56. Aperture 92 is thus aligned
between inlet and outlet collars 44, 48 when tray 58 is fully inserted within
housing 56. A stainless steel mesh screen 96 is mounted in aperture 92 by
fastening apertured frame 98 over screen 96 and to the underside of tray 58,
such that frame 98 circumferentially surrounds aperture 92. A handle 100 is
provided on the forward end 102 of tray 58. The length of housing 56 and
tray 58 (i.e. the displacement between housing 56's rear edges 66, 76 and the
forward end 102 of tray 58) is sufficient to allow handle 100 to protrude
slightly forwardly of dryer 12's front wall 104 when tray 58 is fully inserted
within housing 56. This allows handle 100 to be easily grasped for removal
of tray 58 from housing 56 as explained below.
[0020] During operation of dryer 12, lint-laden exhaust air is expelled
horizontally and rearwardly through dryer 12's exhaust outlet 18 into and
through 90 elbow 40, through conduit 42, through secondary lint trap 46's
inlet collar 44, and through mesh screen 96-which traps lint. Lint-filtered
exhaust air which passes through screen 96 flows through secondary lint trap
46's outlet collar 48, through conduit 50, through 90 elbow 52, into and
through ceiling-embedded vent duct 54 which exhausts the air from the
building.
[0021] After dryer 12 ceases operation, tray 58 can be slidably removed
from housing 56 by grasping handle 100 and pulling tray 58 forwardly
through frontal opening 60. Any lint trapped on screen 96 is removed. Tray
58 is then slidably replaced within housing 56 to realign screen 96 between
inlet and outlet collars 44, 48.
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[0022] As previously mentioned, a stackable laundry washer/dryer unit
is often used to conserve space in a high-rise building suite. Sometimes, a
relatively narrow closet is provided to house the washer/dryer unit. The
closet may have insufficient room for mounting prior art secondary lint trap
16A or 16B in a conveniently accessible position within the closet. However,
if prior art secondary lint trap 16A or 16B is mounted outside the closet, it
may be necessary to use additional 90 elbows, or additional conduit, or
both, to connect dryer 12's exhaust outlet 18 through prior art secondary lint
trap 16A or 16B to a building-embedded vent duct, thus exacerbating the
aforementioned inefficient dryer operation problem. Secondary lint trap 46
overcomes these shortcomings because secondary lint trap 46 can be mounted
inside a narrow closet in a conveniently accessible position atop a stackable
laundry washer/dryer unit housed inside the closet.
[0023] While a number of exemplary aspects and embodiments have
been discussed above, those of skill in the art will recognize certain
modifica-
tions, permutations, additions and sub-combinations thereof. For example,
although it may be convenient to mount housing 56 atop dryer 12, housing 56
may alternatively be mounted above dryer 12 provided inlet and outlet collars
44, 48 extend rearwardly of dryer 12's rear wall 88 to facilitate coupling of
dryer 12's exhaust outlet 18 through one 90 elbow to inlet collar 44 via one
short, substantially straight, elbowless conduit; and facilitate coupling of
outlet collar 48 through one other 90 elbow to vent duct 54 via another
short, substantially straight, elbowless conduit 50. As another example,
although it may be convenient for handle 100 to protrude slightly forwardly
of dryer 12's front wall 104 when tray 58 is fully inserted within housing 56,
handle 100 need only be sufficiently near front wall 104 to facilitate removal
and reinsertion of tray 58 within housing 56. It is therefore intended that
the
following appended claims and claims hereafter introduced are interpreted to
include all such modifications, permutations, additions and sub-combinations
as are within their true spirit and scope.
