Abstrict A desiccant containing cartridge (10) has a cap (12) and a generally
cylindrically cross-sectioned cup (14) for holding desiccant particles
(16) and a dye wafer (18). The cup (14) includes spaced inner and
outer wall portions (20 24) connected by a transverse portion (28)
to define a chamber (30) having an opening (32) for the placement
of a dye wafer (18) and desiccant particles (16). The cap (12) has
a planar portion (52) having outer circumference (53) and inner
circumference (54) defining aperture (55) for receiving inner wall
portion (20) of the cup (14) and being designed for receipt in chamber
(30) to cover opening (32). Cap (12) further includes a peripheral
flanged portion (56) extending transversely from planar portion
(52), and having tabs (100) with an edge portion (102) which permit
cap (12) to cooperate with outer wall portion (24) so that cap (12)
can be retained within chamber (30) in one of a number of axially
spaced positions to prevent shifting of dye wafer (18) and desiccant
(16), thereby leaving a substantial portion of desiccant (16) uncontaminated
and useful for LOI testing.
Claims What is claimed is:
1. A desiccant cartridge comprising: a cup having a spaced inner
and outer wall portion connected by a transverse portion to define
a chamber having an opening; a dye wafer contained within said chamber;
a plurality of desiccant particles contained within said chamber
and about said dye wafer; and a cap having an aperture for slidably
receiving said inner wall portion such that said cap cooperates
with said outer wall portion to provide adjustable, friction mount
of the cap in said cup to prevent shifting of said dye wafer and
said desiccant particles thereby leaving a substantial portion of
said desiccant uncontaminated and useful for LOI testing, wherein
said cap further comprises a planar portion having an inner circumference
defining said aperture and an outer circumference, a peripheral
flanged portion extending transversely from said outer circumference
of said planar portion and said peripheral flanged portion is comprised
of a plurality of spaced-apart tabs, each of said tabs having an
edge portion such that said edge portion cooperates with said outer
wall portion to provide adjustable, friction mount of said cap in
said cup.
2. The desiccant cartridge of claim 1 wherein said edge portion
has an axial thickness extending substantially the entire length
of at least one of said tabs.
3. The desiccant cartridge of claim 1 wherein said tabs are composed
of a flexible plastic.
4. The desiccant cartridge of claim 1 wherein said outer wall
portion is provided with a plurality of outer wall protrusions projecting
radially inwardly therefrom such that said outer wall protrusions
cooperate with said cap.
5. The desiccant cartridge of claim 4 wherein said outer wall
protrusions are arranged in axially-spaced circumferential outer
wall groupings such that said cap can be lockingly retained in one
of a plurality of axially-spaced positions.
6. The desiccant cartridge of claim 1 wherein said outer wall
portion includes a flared lip extending outwardly therefrom.
7. The desiccant cartridge of claim 1 including first and second
plies of permeable lining material for placement in said chamber
to trap said dye wafer and said desiccant particles.
8. The desiccant cartridge of claim 1 including first and second
plies of permeable lining material for placement in said chamber
trapping said dye wafer and said desiccant particles in said chamber.
9. The desiccant cartridge of claim 1 wherein said transverse
portion and said cap include perforations therein.
10. A desiccant cartridge comprising: a cup having a spaced inner
and outer wall portion connected by a transverse portion to define
a chamber having an opening; a plurality of desiccant particles
contained within said chamber; a cap comprising a planar portion
having an outer circumference and an inner circumference defining
an aperture for slidably receiving said inner wall portion, said
cap further comprising a peripheral flanged portion extending transversely
from said outer circumference of said planar portion, said peripheral
flanged portion provided with a plurality of spaced-apart tabs,
each of said tabs having an edge portion whereby said edge portion
cooperates with said outer wall portion to provide adjustable, friction
mount of the cap in said cup after said cap is slid over said inner
wall portion to prevent shifting of said desiccant particles.
11. The desiccant cartridge of claim 10 wherein said outer wall
portion is provided with a plurality of outer wall protrusions projecting
radially inwardly therefrom such that said outer wall protrusions
cooperate with said edge portion of said tabs.
12. The desiccant cartridge of claim 11 wherein said outer wall
protrusions are arranged in axially-spaced circumferential outer
wall groupings such that said tabs can be lockingly retained in
one of a plurality of axially-spaced positions.
13. The desiccant cartridge of claim 10 wherein said edge portion
has an axial thickness extending substantially the entire length
of at least one of said tabs.
14. The desiccant cartridge of claim 10 wherein said tabs are
composed of a flexible plastic.
15. The desiccant cartridge of claim 10 including first and second
plies of permeable lining material for placement in said chamber
to trap the desiccant particles.
16. The desiccant cartridge of claim 10 wherein said transverse
portion and said cap include perforations therein.
17. A desiccant cartridge comprising: a cup having a spaced inner
and outer wall portion connected by a transverse portion to define
a chamber having an opening, said outer wall portion provided with
a plurality of outer wall protrusions projecting radially inwardly
therefrom; a dye wafer contained within said chamber; a plurality
of desiccant particles contained within said chamber about said
dye wafer; a cap comprising a planar portion having an outer circumference
and an inner circumference defining an aperture for slidably receiving
said inner wall portion, said cap further comprising a peripheral
flanged portion extending transversely from said outer circumference
of said planar portion, said peripheral flanged portion provided
with a plurality of spaced-apart tabs, each of said tabs having
an edge portion such that said edge portion cooperates with said
outer wall protrusions of said outer wall portion to provide adjustable,
friction mount of the cap in said cup after said cap is slid over
said inner wall portion thereby preventing shifting of said dye
wafer and said desiccant particles within said chamber and leaving
a substantial portion of said desiccant uncontaminated and useful
for LOI testing.
18. The desiccant cartridge of claim 17 wherein said outer wall
protrusions are arranged in axially-spaced circumferential outer
wall groupings such that said tabs can be lockingly retained in
one of a plurality of axially-spaced positions.
19. The desiccant cartridge of claim 17 wherein said tabs are
composed of a flexible plastic.
20. The desiccant cartridge of claim 17 including first and second
plies of permeable lining material for placement in said chamber
to trap said dye wafer and said desiccant particles.
21. The desiccant cartridge of claim 17 wherein said transverse
portion and said cap include perforations therein.
22. A desiccant cartridge comprising: a cup having a spaced inner
and outer wall portion connected by a transverse portion to define
a chamber having an opening; dye means containing a dye and located
in said chamber; desiccant material disposed in said chamber; and
a cap having an aperture for slidably receiving said inner wall
portion and cooperating with said outer wall to provide adjustable,
friction mount of said cap in said cup thereby compressing said
desiccant and dye means in said cup to inhibit shifting of said
dye means within said chamber thereby leaving a substantial portion
of said desiccant uncontaminated and useful for LOI testing.
23. A desiccant cartridge as recited in claim 22 wherein said dye
means comprise a wafer.
24. A desiccant cartridge as recited in claim 22 wherein said dye
means comprise a pellet.
25. A desiccant cartridge as recited in claim 22 wherein said dye
means comprise powder.
26. A desiccant cartridge as recited in claim 22 wherein said dye
means comprise a permeable bag.
27. A desiccant cartridge as recited in claim 22 wherein said dye
means comprise a capsule.
28. A desiccant cartridge as recited in claim 22 wherein said dye
means comprise a coating on some of said desiccant.
29. A method of making a desiccant cartridge comprising the the
steps of: providing a one-piece cup member including spaced inner
and outer wall portions connected by a transverse portion to define
a chamber having an opening; placing a dye wafer within said chamber;
placing a plurality of desiccant particles within said chamber about
said dye wafer; providing a cap having an aperture for slidably
receiving said inner wall portions, a planar portion having an inner
circumference defining said aperture and an outer circumference,
and a peripheral flanged portion extending transversely from said
outer circumference of said planar portion; and sliding said cap
over said inner wall portion such that said cap cooperates with
said outer wall portion to provide adjustable, friction mount of
the cap in said cup to prevent shifting of said dye wafer and said
desiccant particles within said chamber thereby leaving a substantial
portion of said desiccant uncontaminated and useful for LOI testing,
wherein said peripheral flanged portion with a plurality of spaced-apart
tabs, each of said tabs having an edge portion such that said edge
portion cooperates with said outer wall portion to provide adjustable,
friction mount of the cap in said cup.
30. A method of making the desiccant cartridge in claim 29 further
comprising providing said edge portion with an axial thickness extending
substantially the entire length of at least one of said tabs.
31. A method of making the desiccant cartridge in claim 29 wherein
said tabs are composed of a flexible plastic.
32. A method of making the desiccant cartridge in claim 29 further
comprising providing said outer wall portion with a plurality of
outer wall protrusions projecting radially inwardly therefrom such
that said outer wall protrusions cooperate with said cap.
33. A method of making the desiccant cartridge in claim 32 further
comprising arranging said outer wall protrusions in axially-spaced
circumferential outer wall groupings such that said cap can be lockingly
retained in one of a plurality of axially-spaced positions.
34. A method of making the desiccant cartridge in claim 29 further
comprising placing first and second plies of permeable lining material
in said chamber to trap said dye wafer and said desiccant particles.
35. A method of making the desiccant cartridge in claim 29 further
comprising providing said transverse portion and said cap with perforations
therein.
36. A method for making a desiccant cartridge comprising the steps
of: providing a one-piece cup including spaced inner and outer wall
portions connected by a transverse portion to define a chamber having
an opening; placing a plurality of desiccant particles within said
chamber; providing a cap comprising a planar portion having an outer
circumference and an inner circumference defining an aperture for
slidably receiving said inner wall portion, said cap further comprising
a peripheral flanged portion extending transversely from said outer
circumference of said planar portion, said peripheral flanged portion
provided with a plurality of spaced-apart tabs, each of said tabs
having an edge portion; and sliding said cap over said inner wall
portion such that said edge portion of said tabs cooperates with
said outer wall portion to provide adjustable, friction mount of
the cap in said cup to prevent shifting of said desiccant particles
within said chamber.
37. A method of making the desiccant cartridge in claim 36 further
comprising providing said edge portion with an axial thickness extending
substantially the entire length of at least one of said tabs.
38. A method of making the desiccant cartridge in claim 36 wherein
said tabs are composed of a flexible plastic.
39. A method of making the desiccant cartridge in claim 36 further
comprising providing said outer wall portion with a plurality of
outer wall protrusions projecting radially inwardly therefrom such
that said outer wall protrusions cooperate with said edge portion
of said tabs.
40. A method of making the desiccant cartridge in claim 39 further
comprising arranging said outer wall protrusions in axially-spaced
circumferential outer wall groupings such that said tabs can be
lockingly retained in one of a plurality of axially-spaced positions.
41. A method of making the desiccant cartridge in claim 36 further
comprising placing first and second plies of permeable lining material
in said chamber to trap said desiccant particles.
42. A method of making the desiccant cartridge in claim 36 further
comprising providing said transverse portion and said cap with perforations
therein.
43. A method for making a desiccant cartridge comprising the steps
of: providing a one-piece cup including spaced inner and outer wall
portions connected by a transverse portion to define a chamber having
an opening, said outer wall provided with a plurality of outer wall
protrusions projecting radially inwardly therefrom; placing a dye
wafer within said chamber; placing a plurality of desiccant particles
within said chamber about said dye wafer; providing a cap comprising
a planar portion having an outer circumference and an inner circumference
defining an aperture for slidably receiving said inner wall portion,
said cap further provided with a peripheral flanged portion extending
transversely from said outer circumference of said planar portion,
said peripheral flanged portion provided with a plurality of spaced-apart
tabs, each of said tabs having an edge portion; and sliding said
cap over said inner wall portion such that said edge portion of
said tabs cooperates with said outer wall protrusions to provide
adjustable, friction mount of the cap in said cup to prevent shifting
of said dye wafer and said desiccant particles within said chamber
thereby leaving a substantial portion of said desiccant uncontaminated
and useful for LOI testing.
44. A method of making the desiccant cartridge in claim 43 further
comprising arranging said outer wall protrusions in axially-spaced
outer wall circumferential groupings such that said tabs can be
lockingly retained in one of a plurality of axially-spaced positions.
45. A method of making the desiccant cartridge in claim 43 wherein
said tabs are composed of a flexible plastic.
46. A method of making the desiccant cartridge in claim 43 further
comprising placing first and second plies of permeable lining material
in said chamber to trap the desiccant particles in said chamber.
47. A method of making the desiccant cartridge in claim 43 further
comprising providing said transverse portion and said cap with perforations
therein.
Description BACKGROUND OF THE INVENTION
This invention relates to desiccant cartridges for use in air or
fluid dryers of automotive air conditioning systems.
Desiccants are commonly used in automotive air conditioning systems
for dehydrating air and refrigerants. Desiccant particles are common
in such systems because the high surface area-to-volume ratios of
the particles facilitates their interaction with surrounding air
or fluid. Since the desiccant particles must be held in the air
or fluid stream and prevented from contaminating other parts of
the system, the particles must be held in a container which is permeable
to the air or fluid but impermeable to the particles.
One form of dryer used in automotive air conditioning systems includes
an elongated receiver or accumulator canister having inlet and outlet
ports communicating with the interior of the canister. A desiccant
container is positioned in the interior of the canister and allows
for air and/or fluid through the desiccant material.
One form of package-type desiccant container for use in an accumulator
or receiver dryer is constructed from synthetic felted wool or polyester
which is filled with desiccant and then sealed by stitching or fusing.
One drawback to this form of package is that the felted bag may
not conform to the shape of the canister, so that air or fluid may
bypass the desiccant. Another drawback is that the bag may be non-uniform
in shape, thereby making automatic assembly of the dryer difficult.
If felted polyester is used as a less expensive substitute for
felted wool, the seams of the bag may be formed by ultrasonic welding.
Unfortunately, the reliability of such ultrasonic welds is questionable
and the bag may open up, allowing adsorbent material to escape from
the bag and potentially contaminate the system. In addition, the
felted polyester bag is vulnerable to burn-through when the dryer
is welded shut.
In another proposed form of an accumulator or receiver dryer, desiccant
particles are trapped between a pair of grids or plates which are
welded or press fit inside the canister. According to one embodiment,
the desiccant is charged by pouring the desiccant particles into
the canister once a first of the grids or plates is positioned.
A pipe extends through holes in the grids or plates to exhaust dried
air to an outlet port.
A dryer of this form is likely to be difficult to assemble because
the grids or plates must be slid into position and, in some cases,
welded inside the canister. Further, since the desiccant particles
are manually poured into the container, the desiccant must be pre-measured
due to the difficulty of controlling the amount of desiccant poured
into the canister based on visual observation alone. The pouring
of the desiccant creates a risk of accidental contamination outside
the accumulator since desiccant particles may fall into the pipe
communicating with the outlet port. Nevertheless, the amount of
desiccant poured into the canister may vary from canister to canister
for at least the reasons mentioned above.
U.S. Pat. No. 5522204 the contents of which are hereby incorporated
by reference, discloses a desiccant cartridge which can be inserted
within an accumulator or receiver dryer. The desiccant cartridge
includes a cup for holding particulate desiccant and a cap which
is locked to the cup by an integral detent on an inner wall portion
of the cup.
U.S. Pat. No. 5529203 the contents of which are hereby incorporated
by reference, also discloses a desiccant cartridge which can be
inserted within an accumulator or receiver dryer. The desiccant
cartridge includes a cup for holding particulate desiccant and a
cap. The cap is designed for receipt in the chamber to cover the
opening. In addition, the cap has a hole for receiving the inner
wall portion of the cup. The cup includes a number of nib segments
which are arranged into axially spaced nib groupings. The cap includes
an edge portion which permits the cap to be retained between axially
adjacent nib groupings thus retaining the cap within the cup in
one of a number of axially spaced positions.
The desiccant particles are either poured directly into the cup,
or into a felted bag which in turn is inserted into the cup before
the desiccant cartridge is inserted within the receiver dryer. It
is important that desiccant not shift once the cap is locked into
place. If there is not enough desiccant to fill the predetermined
volume, or if the desiccant should settle over time, then the desiccant
within the container will undesirably shift within the chamber.
It has become increasingly popular and effective to place leak
detection dyes in desiccant packages so that leaks in the air conditioning
system can be readily identified. These dyes can be adsorbed into
a host wafer of a substrate material, take the form of a powder
or as a solid pellet, and such and are placed directly into the
desiccant package during assembly. During operation of the air conditioning
system, the dye mixes and circulates with the refrigerant which
will be carried outside if there is a leak. These dyes illuminate
under long wave ultra-violet light, as such, the leak in an air
conditioning system can be located when long wave ultra-violet light
is used. One popular leak detection dye is a fluorescent alkyl substituted
perylene dye that dissolves in the refrigerant and flows through
the refrigeration system as disclosed in U.S. Pat. No. 5650563.
The contents of which are hereby incorporated by reference herein.
In these desiccant packages, when dye impregnated wafers, pellets,
or the like, are inserted to provide for the desired leak detection
requirements, the dye can migrate throughout the package contaminating
almost all of the desiccant particles.
This dye migration does not normally interfere with the proper
functioning of the desiccant. However, auto and truck manufacturers
often perform loss on ignition (LOI) tests on the desiccant to assess
the amount of moisture retention therein. This moisture amount is
determined by the weight difference obtained before and after drying
a desiccant sample at a specified temperature and for a specified
period of time to achieve a constant weight. The difference in weight,
calculated as a percentage of the sample's initial weight, after
being dried, is reported as LOI.
The problem is that when the dye migrates throughout a package
or container, contaminating a substantial quantity of the desiccant
particles, virtually no particles or an insufficient number of same
are left so that accurate LOI testing can be conducted thereon.
As such, dye from a dye wafer that has contaminated the desiccant
particles results in false LOI readings since the analytical equipment
utilized will regard the dye as being water.
Accordingly, there is a need in the art to provide a desiccant
cartridge which is simple to assemble with means for retaining a
cap such that the cartridge can house both desiccant particles and
a leak detection dye wafer, or the like,wherein the cap prevents
the dye wafer from shifting and contaminating an excessive quantity
of the desiccant particles.
SUMMARY OF THE INVENTION
These drawbacks and others are overcome by means of the present
invention embodied in a desiccant containing cartridge.
The desiccant cartridge includes a cup extending along an axis
and having spaced inner and outer wall portions connected by a transverse
portion to define a chamber having an opening for the placement
of a dye wafer and desiccant particles, and a cap for receipt in
the chamber. The cap has a planar portion having an outer circumference
and an inner circumference defining an aperture for receiving the
inner wall portion of the container when the cap is received in
the chamber.
Both the transverse portion and the cap are perforated to allow
air or fluid to reach the desiccant housed thereon. The outer wall
portion of the cup also may include a plurality of outer wall protrusions
including, but not limited to, ribs, nibs, beads, bumps or other
equivalent protrusions projecting radially inwardly from the outer
wall portion which engage and retain the cap in one of a number
of axially spaced positions to prevent shifting of the particulate
desiccant and the dye wafer within the chamber. The inner wall portion
also may include a plurality of inner wall protrusions to help retain
the cap. Preferably, the inner and outer wall protrusions are arranged
in axially-spaced circumferential groupings.
By reason of the ability of the cap to be adjusted to a position
that prevents shifting of the dye barrier and desiccant, a substantial
portion of the desiccant material is not coated with the dye and
thereby these uncoated particles may be removed from the cartridge
and satisfactory LOI testing conducted thereon.
A preferred embodiment of the desiccant cartridge consists of a
cup extending along an axis and having spaced inner and outer wall
portions connected by a transverse portion to define a chamber having
an opening for the placement of a dye wafer and desiccant particles,
and a cap consisting of a planar portion having an outer circumference
and an inner circumference defining an aperture for receiving the
inner wall portion when the cap is received in the chamber. The
cap further is provided with a peripheral flanged portion extending
transversely from the outer circumference of the planar portion.
The peripheral flanged portion having spaced apart locking tabs
each with an edge portion that is adapted to fit contiguously with
the outer wall portion of the cartridge.
As such, it is one object of the invention to provide a desiccant
cartridge which is simple to assemble, and allows for the user to
compress the cap into the cup to sufficiently eliminate empty space
within the chamber.
It is another object of the invention to prevent the shifting of
the dye wafer and desiccant particles, thus, eliminating attrition
of the desiccant and allowing satisfactory LOI testing to be conducted
thereon.
This invention also eliminates the need for external springs or
other devices that add more cost to the cartridge.
Lastly, since the cup-shaped cartridge is formed into a specific,
definite shape and dimension depending on the particular canister
in which it is to be housed, the air or refrigerant system is efficient,
minimizing by-pass of the fluid flow from the desiccant particles
which can in some cases occur.
The invention will be further described in conjunction with the
appended drawings and following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of one embodiment of a desiccant
cartridge of the present invention;
FIG. 2 is a cross-sectional view of the desiccant cartridge of
FIG. 1 taken along the plane represented by lines and arrows 2A--2A
in FIG. 1;
FIG. 3 is a top plan view of the desiccant cartridge of FIG. 1
without the cap installed;
FIG. 4 is a top perspective view of the cap of FIG. 1;
FIG. 5 is a top perspective view of another embodiment of a cap
for a desiccant cartridge;
FIG. 6 is a bottom plan view of the cap of FIG. 5;
FIG. 7 is a top perspective exploded view assembly of a desiccant
cartridge shown in combination with the cap of FIG. 5 and a canister
of an accumulator or receiver dryer;
FIG. 8 is a cross-sectional view of the desiccant cartridge of
FIG. 7 installed in a canister of an accumulator or receiver dryer;
FIG. 9 is an enlarged partial cross-sectional view of the cap of
FIG. 5 being retained in another embodiment of the cartridge of
FIG. 7 having inwardly facing outer wall protrusion groupings (bumps
shown here);
FIG. 10 is an exploded perspective view of the preferred cartridge
and cap in accordance with the invention;
FIG. 11 is a cross sectional view taken along a plane dissecting
the axis of the cartridge and cup combination shown in FIG. 10;
FIG. 12 is a schematic top view of the cap shown in the combination
shown in FIG. 10 showing the top side array of annular openings
therein;
FIG. 13 is a schematic illustration of the bottom side view of
the cap shown in the combination of FIG. 10 here detailing the
bottom side array of petal or kidney shaped openings that will be
placed adjacent the filter medium; and
FIG. 14 is a magnified view of one of the petal or kidney shaped
openings shown in FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-14 illustrate a desiccant cartridge 10 which comprises
a cap 12 and a generally cylindrically cross-sectioned cup 14 for
holding desiccant particles 16 and a dye wafer 18.
As seen in FIG. 2 the cup 14 is a one-piece plastic molding which
includes a cylindrical inner wall portion 20 extending along a central
axis 22 a cylindrical outer wall portion 24 concentric with the
inner wall portion 20 and a bottom defined by a transverse portion
28 which joins the inner wall portion 20 to the outer wall portion
24. The inner and outer wall portions 2024 and the transverse portion
28 cooperate to define a chamber 30 having an opening 32 for receiving
the desiccant 16 and dye wafer 18.
The outer wall portion 24 of the cup includes at least one outwardly
flared lip portion 34. The flared lip portion 34 is adapted to resiliently
fit within a dryer canister 36 (FIG. 7) of an air conditioning or
refrigeration system (not shown).
Thus, the desiccant cartridge 10 is retained within the dryer canister
36 (FIG. 8) by means of a friction or interference fit provided
by the flared lip portion 34. The lip portion 34 also serves as
a continuous annular seal to prevent air or fluid escape that may
otherwise occur along the interface between the circumference of
the cup 14 and the dryer canister 36. Although the lip 34 is shown
at the top of the cup, it can be located anywhere along the axial
length dimension of the cup.
As best shown in FIG. 2 the cylindrical outer wall portion 24
of the cup 14 may include a plurality of circumferentially spaced-apart
outer wall protrusions 38 such as ribs, ribs, beads, bumps or other
equivalent protrusions projecting radially inwardly from an inner
surface 40 of the outer wall portion 24. The protrusions 38 are
arranged in axially-spaced outer wall protrusion groupings 42 and
are oriented in a common plane which extends transverse to the central
axis 22. As discussed further below, the protrusions 38 permit the
cap 12 to be retained within the chamber 30 in one of several positions
to reduce or prevent movement or shifting of the desiccant particles
16 and dye wafer 18 within the chamber 30. The artisan will appreciate
that the inner wall portion 20 also may include a plurality of circumferentially
spaced-apart inner wall protrusions (not shown) arranged in axially-spaced
inner wall protrusion groupings 43 equivalent in form and function
to the outer wall protrusions 38.
In FIG. 2 the inner wall portion 20 serves as a sleeve 44 for
receiving a portion of an aluminum pipe or conduit 45 (FIG. 8) which
communicates with an outlet port (not shown) of the air conditioning
or refrigeration system. As shown, the inner wall portion 20 includes
a stepped inner surface 46 which defines an intermediate shoulder
or flange 48. Thus, the stepped inner surface 46 has two inner diameters
D.sub.1 and D.sub.2 wherein D.sub.1>D.sub.2. The inner diameter
D.sub.1 is substantially equal to or slightly larger than the outer
diameter of the aluminum pipe or conduit 45. The aluminum pipe or
conduit 45 (FIG. 8), when inserted into the inner wall portion 20
abuts against the shoulder 48 to urge the desiccant container 10
downwardly within the dryer canister 36.
The inner wall portion may also include an annular band or ring
shaped flange reducing the inside diameter of the sleeve. This serves
as an aid in locking or securing frictionally fitting the requisite
accumulator or receiver-dryer tube therein.
As best shown in FIG. 8 the inner wall portion 20 and aluminum
pipe or conduit 45 cooperate to define a continuous axially extending
fluid passage 50.
As shown in FIG. 2 the dye is in the form of a wafer 18 but the
artisan will appreciate that the dye may be present in a variety
of physical forms such as a pellet, powder, permeable bag, capsule,
etc. or the dye may simply be coated onto a few of the desiccant
particles 16 themselves. Attention again is directed to U.S. Pat.
No. 5650563 (Cooper et al.) and its disclosure of a variety of
useful dyes and physical forms thereof that may be used to achieve
the desired leak detection function.
As shown in FIGS. 1 and 4 the cap 12 conforms to the circular
shape of the cup 14 and has a planar portion 52 having an outer
circumference 53 and an inner circumference 54 defining an aperture
55 for receiving the inner wall portion 20 when the cap 12 is received
in the chamber 30. The cap 12 further is provided with a peripheral
flanged portion 56 extending transversely from the outer circumference
53 of the planar portion 52 and having a continuous edge portion
58 which cooperates with the outer wall portion 24 to retain the
cap 12 to the cup 14.
In another embodiment, as shown in FIGS. 5 and 6 the peripheral
flanged portion 56 has a plurality of spaced-apart tabs 100 each
with an edge portion 102 which cooperates with the outer wall portion
24 to positively lock the cap 12 to the cup 14 as shown in FIG.
8. That is, the outer diameter of the edge portion 102 is greater
than the inner diameter of the outer wall portion 24. These tabs
100 are composed of a flexible plastic and, in effect, provide a
spring like action as they are compressed for sliding, positioning
or mounting along the container axis. Further, the edge portions
102 of any one tab 100 may vary in axial thickness 104 causing an
edge portion 102 to extend substantially the entire length of the
tab 100. As such, the greater the axial thickness 104 of the edge
portion 102 the more surface area which cooperates with the outer
wall portion 24 to provide a greater spring like action whereby
the cap 12 can be retained more positively providing for better
cap retention.
As shown in FIG. 9 if the cylindrical outer wall portion is provided
with a plurality of circumferentially spaced-apart outer wall protrusions
38 the edge portion 102 of the tabs 100 simply pass over the outer
wall protrusion groupings 42 when sufficient force is applied to
the cap 12. Depending upon the position of the cap 12 in the chamber
30 and upon the axial thickness 104 of an edge portion 102 an edge
portion 102 may be lockingly retained between axially adjacent outer
wall protrusion groupings 42 or an edge portion 102 may abut against
an outer wall protrusion grouping 42 thereby retaining the cap
12 in one of many axially-spaced positions to prevent shifting of
the dye wafer 18 and desiccant particles 16. The cooperation of
and the positioning of the portions 102 relative to the protrusions
42 operate to provide a downwardly (with respect to the figure)
and axially directed compressive force on the lining 68 and desiccant
material 16.
As shown in FIGS. 4 and 5 the artisan will appreciate that the
cap 12 can be even further provided with a similar central flanged
portion 60 extending transversely from an inner circumference 54
of the planar portion 52 with the central flanged portion 60 having
one continuous edge portion 62 or spaced-apart tabs each with an
edge portion (not shown), which cooperates with the inner wall portion
20 or inner wall protrusions 43 to help facilitate cap retention
and to help prevent shifting of the dye wafer 18 and desiccant particles
16.
In FIGS. 3-6 the transverse portion 28 of the cup 14 and the planar
portion 52 of the cap 12 are each perforated with a number of symmetrically
arranged ports or perforations (64 and 66 respectively) so that
the planar portion 52 and the transverse portion 28 are each permeable
to the air or fluid to be dried. In the embodiment shown in FIG.
5 the ports 66 of the cap are arranged in one concentric annular
row such that the row has eight s-shaped ports. The precise arrangement
and shapes of the ports 64 66 is not critical to the operation
of the desiccant cartridge 10 as long as the desiccant 16 remains
contained and air or fluid (not shown) is allowed to enter the cartridge
10 interact evenly with the desiccant 16 and exit from the cartridge
10.
As shown in the embodiments of FIGS. 2 and 8 plies of a permeable
lining material 68 70 such as felted polyester or gauze can be
placed inside the chamber 30 near the transverse portion 28 and
the cap 12 to trap the desiccant 16 in the cartridge 10. The lining
material 68 70 must be permeable to the air or fluid (not shown)
to be dried but impermeable to the particulate desiccant 16. If
gauze is used, the mesh size of the gauze must be significantly
smaller than the grain size of the desiccant 16.
When the desiccant cartridge 10 is charged with the particulate
desiccant 16 the first ply of the permeable lining material 70
can be inserted by sliding it down the inner wall portion 20 until
positioned adjacent the transverse web portion 28. The dye wafer
18 is first placed into the chamber 30 and next the required amount
of desiccant 16 is poured therein. Once the desiccant 16 is charged,
the second ply of the permeable lining material 68 can be slid down
the inner wall portion 20 against the desiccant 16.
The cap 12 is then inserted into the chamber 30 such that the inner
wall portion 20 extends through the aperture 55 in the cap 12. As
the cap 12 is urged downwardly toward the transverse portion 28
the edge portion 58 102 passes radially inwardly and slides along
the outer wall portion 24 until the planar portion 52 of the cap
12 abuts against the charged desiccant 16. As such, the cap 12 abuts
against the second ply 68 while the edge portion 58 102 thereof
lockingly secures the dye wafer 18 in the mass of desiccant 16.
Once the desiccant cartridge 10 is assembled, it can then be inserted
into a dryer canister 36 as shown in FIG. 8. The outwardly flared
lip portion 34 resiliently bears against an inside surface 72 of
the dryer canister 36 to provide a snug fit of the desiccant container
10 in the dryer canister 36. The lip portion 34 also serves to prevent
air or fluid from bypassing the desiccant container 10 so as to
ensure passage thereof through the chamber 30 and over the desiccant
particles 16.
In the embodiment shown in FIG. 2 the aluminum pipe or conduit
45 is inserted into the inner wall portion 20 until the pipe 45
abuts against the shoulder 48. The desiccant container 10 is then
urged downwardly into the canister 36 until it abuts against the
closed end portion 74 of the canister 36.
The cup 14 may be vibrator or bowl fed to a robotic arm (not shown)
for automatic installation into the dryer canister 36. The cup 14
may be sized to fit snugly in the canister 36 to inhibit bypass
flow of air or fluid (not shown) to be dried. The means for detaining
the cap 12 on the cup 14 is highly reliable such that dye contamination
of the desiccant 16 from the dye wafer 18 is minimized. As a result,
the non-contaminated desiccant particles can be accessed for reliable
LOI testing.
Tuning now to the preferred embodiment shown in FIGS. 10-14 and
with specific attention to FIGS. 10 and 11 cup 502 is composed
preferably of polypropylene, although polyester may also be mentioned
as another polymer that may be used. Desiccant material 504 is interposed
between dual density fiberglass laminates 506 508 on the center
axially disposed tube 510 of the cup.
The laminates 506 508 are composed of a high density layer 512
and low density fiberglass batting layer 514 that have been laminated
together via hot bonding or other bonding techniques. These laminates
are available from Johns Manville under the Tuff Skin designation.
The desiccant material 504 comprises beads that are commercially
available from Universal Oil Products under the XH7 designation.
The lid 516 composes a plurality of lock tabs 550. Bottom 520 of
the cup comprises a multiplicity of openings therein that roughly
correspond in shape and size to those provided in the lid.
The lid is snugly and adjustably mounted in the i.d. of the cartridge.
The position of the lid along the axis of the cartridge may be varied.
Accordingly, the lid may be snugly secured over a host of different
desiccant volumes that may be provided in the cup.
The interior diameter of the cup or cartridge may be provided with
an uneven, roughened surface texture 522 as shown by generally parallel
ridges or grooves to increase the friction between the outer periphery
of the lid and the cartridge walls. Bumps or other protrusions may
be formed along the cartridge walls for this purpose.
As best shown in the FIG. 10 drawing, the circumferential wall
or skirt 548 of the lid that is adapted to fit snugly with the inner
wall of the cartridge is provided with a plurality of lock tabs
550 that are spaced from each other around the skirt. Each of the
lock tabs protrudes radially outwardly from the skirt relative to
the radial dimensions of the skirt. The tabs are composed of a flexible
plastic and, in effect, provide a spring like action as they are
compressed for sliding, positioning or mounting along the cartridge
axis. The locking tabs cooperate with the textured inside surface
of the cartridge to provide adjustable, friction mount of the lid
along the axis of the cartridge.
An annular flange 800 is provided around the circumference of the
cup and is composed of a flexible resilient plastic. The flange
provides a snug fit within the surrounding canister or housing (not
shown).
As shown, the cap is provided with a multiplicity of oblong, petal
shaped apertures 560 (see FIG. 13) generally disposed with their
major axes radially extending from the inner tube 510 toward the
circumference of the cap. Superposed over the array of the petal
shaped apertures are a plurality of concentric, annular openings
562 (see FIG. 12). The openings 562 are narrower than the width
or minor axis of the openings 560.
The structure thus provides two levels of aperture depths. The
first level is defined by the openings 562 and the solid concentric
rings or ridges 564 that separate neighboring openings 562. The
second level is defined by the generally oblong apertures 560 and
the generally radially extending ridges 566 separating neighboring
openings 560 from each other.
The surface area provided by the sum of the openings 560 is greater
than the sum of the areas of the openings 562. This allows for the
desired fluid flow volume through the cap, while the relatively
narrow openings between the ridges 564 still serve to retain desiccant
beads in the cup enclosure.
Similarly, the bottom 520 of the cup is also provided with this
bi-level arrangement of openings wherein the relatively large petal
shaped openings 560 are provided adjacent the fiberglass filter
laminate 508 and with the annular openings provided under the array
of openings 560 on the bottom side of the cup. Once again, the large
surface area provided by the openings 560 will permit the desired
volumetric flow of fluid through the cup with the narrower openings
562 serving as a retention cage to minimize desiccant loss through
the bottom of the cup.
With specific reference drawn to FIG. 12 the annular array of openings
that are provided on the top of the cap and bottom of the cup are
shown. Here, the openings 562 are presented in the form of concentric
rings adapted for coaxial alignment with the inner tube 510. Each
of the ring shaped openings is separated from its neighboring opening
by a ring 564.
In FIG. 13 the petal shaped arrangement of openings adapted for
placement adjacent the filter media is shown. Here petals or kidneys
560 are generally oblong and radially disposed about the axis represented
by the inner tube 510. The petals 560 have a major axis 702 extending
generally radially and a minor axis 704 transverse to the major
axis (FIG. 14). Individual petals or openings 560 are separated
from neighboring openings in the array by generally extending ridge
members 566.
The depth dimension (or axial dimension) of the ridge members 566
is greater than the depth dimension (axial dimension) of the rings
564.
The bead cage or bi-level arrangement of openings in the cap and
cartridge bottom creates a large exposed area against the filter
media, thus increasing efficiency and reducing pressure drop, and
it also creates a reduced area small enough that a bead could not
pass through. This reduced area section is not against the filter
media and therefore does not reduce its efficiency.
The thickness of the filter retainer is used to create a transition
between the larger open area against the filter media and the reduced
area that is not against the filter media. The smaller openings
do not allow the small beads to pass through, but at the same time,
since they are not reducing filter surface area, they do not cause
a reduction in filter efficiency and pressure drop.
Various changes or modifications in the invention described may
occur to those skilled in the art without departing from the true
spirit or scope of the invention. The above description of preferred
embodiments of the invention is intended to be illustrative and
not limiting, and it is not intended that the invention be restricted
thereto but that it be limited only by the true spirit and scope
of the appended claims. |