Abstrict A desiccant cartridge (10) having a seal (12) therearound for forming
a proper seal between cartridge (10) and canister (14) of a receiver/dryer
or accumulator assembly includes a cup (16) extending along an axis
(18) having inner wall portion (20) and outer wall portion (22)
connected to transverse portion (24) to define a chamber (26) containing
desiccant particles (30). Cap (70) is secured to cup (16) to secure
the desiccant particles (30) inside chamber (26). Outer wall portion
(22) is provided with the seal (12) that is composed of a flexible
thermoplastic elastomer that is resistant to heat during welding
shut of the canister (14).
Claims 1. A desiccant cup comprising: a spaced inner and outer wall portion
connected by a transverse portion to define a chamber having an
opening, said outer wall portion including an outer surface; and
a seal cooperating with said outer surface of said outer wall portion
and located intermediate said opening and said transverse portion
for cooperating with a canister to form a seal therebetween, said
seal comprising a thermoplastic elastomer.
2. The desiccant cup as recited in claim 1 wherein said thermoplastic
elastomer is SANTOPRENE.RTM..
3. The desiccant cup as recited in claim 1 wherein said seal includes
a body and a lip, said lip projecting outwardly from said body and
away from said outer wall portion.
4. The desiccant cup as recited in claim 3 wherein said body is
continuous and annular and further has opposing first and second
longitudinal side edges, said lip extending outwardly from one of
said side edges and in a direction towards the opposite side edge
such that a cross-section of the seal is substantially v-shaped.
5. The desiccant cup as recited in claim 1 wherein said seal is
detachably removable.
6. The desiccant cup as recited in claim 5 wherein said seal includes
a body and a lip projecting outwardly from said body and away from
said outer wall portion, said body having an inner surface defining
an inner diameter and said outer wall portion having said outer
surface defining an outer diameter, said inner diameter being less
than said outer diameter thereby creating a stretch fit for said
seal around said outer surface.
7. The desiccant cup as recited in claim 1 wherein said outer wall
portion includes a seal stop protruding outwardly from said outer
surface intermediate said opening and said transverse portion for
limiting axial movement of said seal along said outer surface, said
seal being positioned intermediate said seal stop and said opening.
8. A desiccant cartridge adapted for snug reception within a canister
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 including an outer surface, said cup further
having a seal cooperating with said outer surface of said outer
wall portion and located intermediate said opening and said transverse
portion for cooperating with said canister to form a seal therebetween,
said seal comprising a thermoplastic elastomer; and a cap having
an aperture for slidably receiving said inner wall portion.
9. The desiccant cartridge as recited in claim 8 wherein said thermoplastic
elastomer is SANTOPRENE.RTM..
10. The desiccant cartridge as recited in claim 8 wherein said
seal includes a body and a lip, said lip projecting outwardly from
said body and away from said outer wall portion.
11. The desiccant cup as recited in claim 10 wherein said body
is continuous and annular and further has opposing first and second
longitudinal side edges, said lip extending outwardly from one of
said side edges and in a direction towards the opposite side edge
such that a cross-section of the seal is substantially v-shaped.
12. The desiccant cup as recited in claim 8 wherein said seal is
detachably removable.
13. The desiccant cup as recited in claim 12 wherein said seal
includes a body and a lip projecting outwardly from said body and
away from said outer wall portion, said body having an inner surface
defining an inner diameter and said outer wall portion having said
outer surface defining an outer diameter, said inner diameter being
less than said outer diameter thereby creating a stretch fit for
said seal around said outer surface.
14. The desiccant cup as recited in claim 8 wherein said outer
wall portion includes a seal stop protruding outwardly from said
outer surface intermediate said opening and said transverse portion
for limiting axial movement of said seal along said outer surface,
said seal being positioned intermediate said seal stop and said
opening.
15. A desiccant cup comprising: a spaced inner and outer wall portion
connected by a transverse portion to define a chamber having an
opening, said outer wall portion including an outer surface; and
a seal cooperating with said outer surface of said outer wall portion
and located intermediate said opening and said transverse portion,
said seal including a body and a lip, said lip projecting outwardly
from said body and away from said outer wall portion for cooperating
with a canister to form a seal therebetween.
16. The desiccant cup as recited in claim 15 wherein said seal
comprises a thermoplastic elastomer
17. The desiccant cup as recited in claim 16 wherein said thermoplastic
elastomer is SANTOPRENE.RTM..
18. A desiccant cartridge adapted for snug reception within a canister
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 including an outer surface, said cup further
having a seal cooperating with said outer surface of said outer
wall portion and located intermediate said opening and said transverse
portion, said seal including a body and a lip, said lip projecting
outwardly from said body and away from said outer wall portion for
cooperating with a canister to form a seal therebetween; and a cap
having an aperture for slidably receiving said inner wall portion.
19. The desiccant cartridge as recited in claim 18 wherein said
seal comprises a thermoplastic elastomer.
20. The desiccant cartridge as recited in claim 19 wherein said
thermoplastic elastomer is SANTOPRENE.RTM.
Description CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 60/404176 filed Aug. 16 2002.
FIELD OF THE INVENTION
[0002] This invention relates generally to desiccant cartridges
for use in canisters of receiver/dryers or accumulator assemblies
of automotive air conditioning systems. More specifically, it relates
to a desiccant cartridge having a seal therearound for forming a
seal between the cartridge and canister.
BACKGROUND OF THE INVENTION
[0003] Desiccant cartridges containing desiccant particles are
common in automotive air conditioning systems for dehydrating refrigerants.
These desiccant cartridges are adapted to fit within canisters of
receiver/dryer (R/D) and accumulator assemblies.
[0004] Although various forms of R/D and accumulator assemblies
have been suggested in the prior art, the types used in automotive
air conditioning systems generally include an elongated canister
having inlet and outlet ports communicating with the interior thereof.
The outlet port may consist of a fluid flow tube used to return
the air or fluid flowing from the entry end of the canister to the
exit end. A desiccant cartridge holding desiccant particles is positioned
in the interior of the canister allowing for air or fluid to move
through the desiccant particles.
[0005] Desiccant containing cartridges such as those shown in U.S.
Pat. Nos. 5814136; 5716432; 5685087; 5569316; 5540348;
5529203; and 5522204 are disposed in the R/D and accumulator
assemblies and function to dry the liquid refrigerant as it passes
from the assembly inlet through to an outlet port contained in the
structure.
[0006] Some dryer canisters are welded shut after the desiccant
cartridge is inserted. Notably, the heat created from the welding
process can be problematic in that it may result in detrimental
dimensional changes to the desiccant cartridge resulting in an improper
seal between the cartridge and canister. It is important that the
desiccant cartridge conform to the dimensions of the canister in
order to form a secure fit within the canister and to form a proper
seal between the cartridge and the canister. An improper seal can
cause leakage within the receiver/dryer or accumulator assembly,
or into the environment. Internal leakage can create icing within
the air conditioning system, and environmental leakage can create
a loss in fluid pressure as well as create potential health and
environmental risks. As such, an improper seal can reduce the effectiveness
of the air conditioning system.
[0007] To keep a desiccant cartridge secure within a receiver dryer
or accumulator assembly and form a proper seal, desiccant cartridges
have employed various retention or sealing devices. One type of
sealing device used on today's desiccant cartridges includes a continuous
flange, or seal, made of polypropylene plastic. The seal is provided
on the outer wall of the desiccant cartridge and is intended to
provide a seal between the cartridge and the canister. However,
the polypropylene is somewhat rigid such that the seal can be damaged
when the desiccant cartridge is installed in a canister thereby
creating an improper seal. Also, the polypropylene has a tendency
to curl and harden from heat during welding shut of the canister
resulting in detrimental dimensional changes to the seal.
[0008] Notably, the desiccant cartridge of the present invention
includes a seal of high heat resistance and excellent flexibility
thereby avoiding detrimental dimensional changes to the seal and
improper sealing between the cartridge and the canister. This seal
preferably is a thermoplastic elastomer, most preferably SANTOPRENE.RTM..
SUMMARY OF THE INVENTION
[0009] These drawbacks and others are overcome by means of the
present invention embodied in a desiccant containing cartridge.
[0010] The desiccant cartridge of the present invention 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. The inner wall portion defines an elongated center
tube with opposing first and second ends wherein the first end extends
beyond an upper edge of the outer wall and the second end extends
away from a bottom surface of the transverse portion. The outer
wall portion has an outer surface defining an outer diameter and
a seal therearound intermediate the opening and transverse portion
for cooperating with a canister to form a proper seal between the
cartridge and the canister.
[0011] The seal is preferably comprised of a thermoplastic elastomer,
most preferably SANTOPRENE.RTM., which is available from Advanced
Elastomer Systems, L.L.P., located in the U.S. in Akron, Ohio and
Auburn Hills, Mich. The SANTOPRENE.RTM. product is superior to today's
polypropylene flanges, or seals, insofar as the SANTOPRENE.RTM.
provides greater heat resistance and flexibility. Specifically,
SANTOPRENE.RTM. offers a constant service temperature range (-81
F to 275 F) with no cracking or tackiness; has excellent resistance
to cut growth while flexing; has high tear strength and superior
resistance to fatigue; and a wide range of flexibility, among other
favorable characteristics.
[0012] The seal includes a continuous body, preferably annular
in shape, having opposing first and second longitudinal side edges
and an inner surface defining an inner diameter. The seal further
includes a lip extending outwardly from the body. Preferably, the
lip extends outwardly from one of the side edges and in a direction
towards the opposite side edge such that a cross-section of the
seal reveals a substantially v-shape. The seal preferably is removably
detachable from the cartridge. The inner diameter of the seal is
less than the outer diameter of the cartridge in order to create
a stretch fit for the seal around the outer surface of the outer
wall portion. The seal preferably is positioned around the outer
wall portion of the cartridge such that the body is situated adjacent
the outer surface and the lip extends outwardly from the body and
away from the cartridge in a direction, preferably, towards the
opening.
[0013] A cap is provided for receipt in the chamber and is secured
to the cup to retain desiccant inside the chamber. Both the cap
and the transverse portion are perforated to allow air or fluid
to reach the desiccant housed therein.
[0014] Accordingly, the desiccant cartridge of the present invention
is designed to be used in combination with a R/D or accumulator
canister including an outer wall axially disposed. The canister
further has a bottom wall cooperating with the outer wall to define
a chamber having an opening. The canister further is provided with
a lid having an outlet port therein, preferably centrally located.
During assembly the lid is secured, preferably by welding, to the
canister opposite the bottom wall to seal the chamber.
[0015] Prior to placing and welding the top wall onto the canister
to complete assembly of the R/D or accumulator, an assembled desiccant
cartridge, preferably having a SANTOPRENE.RTM. seal, is placed within
the chamber so that the seal cooperates with the inner surface of
the dryer canister forming a proper seal therebetween.
[0016] Accordingly, it is one object of the invention to provide
a desiccant cartridge including a seal of high heat resistance and
excellent flexibility thereby avoiding detrimental dimensional changes
to the seal and improper sealing between the cartridge and the canister.
[0017] Also, it is another object of the invention to provide a
universal size cartridge having such a seal so that the cartridge
will be adapted to fit substantially all of the commercially available
accumulator and receiver/dryer canisters.
[0018] Lastly, it is another object of the invention to allow customers
to purchase just one size desiccant cartridge provided with such
a seal so that the cartridge can fit a broad range of canister sizes.
[0019] The invention will be further described in conjunction with
the appended drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of the desiccant cartridge
of the present invention;
[0021] FIG. 2 is a perspective view of the seal of the present
invention;
[0022] FIG. 3 is a cross-sectional view of the seal of FIG. 2 taken
along lines 3-3;
[0023] FIG. 4 is a cross-sectional view of the desiccant cartridge
of FIG. 1 taken along lines 4-4; and
[0024] FIG. 5 is a cross-sectional view of the desiccant cartridge
of FIG. 1 installed in a canister of a R/D or accumulator assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] FIGS. 1-5 illustrate the desiccant cartridge 10 of the present
invention having a seal 12 therearound for forming a proper seal
between the desiccant cartridge 10 and a canister 14 of a R/D or
accumulator assembly (not shown).
[0026] In FIGS. 1 and 4 the desiccant cartridge 10 includes a
cup 16 extending along an axis 18 and has spaced inner and outer
wall portions 20 and 22 connected by a transverse portion 24 to
define a chamber 26 (FIG. 4) having an opening 28 for receiving
desiccant particles 30 (FIG. 4). The cup 16 is a one-piece plastic
molding preferably formed from polypropylene by conventional molding
techniques, although polyester may also be mentioned as another
polymer that may be used. FIG. 4 shows that a leak detection dye
32 in the form of a wafer, or the like, may also be placed within
the chamber 26. The dye wafer 32 is used to identify leaks in the
air conditioning system (not shown).
[0027] As best shown in FIG. 4 the inner wall portion 20 defines
an elongated center tube 34 with opposing first and second ends
36 and 38 wherein the first end 36 extends beyond an upper edge
40 of the outer wall 22 and the second end 38 extends away from
a bottom surface 42 of the transverse portion 24 thereby providing
a simple way for replacing a metal fluid flow tube (not shown) while
at the same time reducing the material, manufacturing, handling
and assembly costs associated therewith. The first end 36 preferably
is formed from a high temperature resistant plastic, such as a polypropylene/nylon
blend. Here, the first end 36 has been molded separately from the
cup 16 then press fit to the inner wall portion 20 opposite the
second end 38 to form a center tube 44 such that the first end 36
comprises a high temperature resistant plastic.
[0028] As shown in FIG. 5 the first end 36 is shaped to receive
a temperature resistant o-ring 46 to further protect and insulate
the first end 36 from heat during welding of a lid 48 onto the canister
14. The high temperature o-ring 46 preferably is made from a high
temperature HNBR rubber material available from Parker.
[0029] In FIG. 1 the outer wall portion 22 of the cartridge 10
has an outer surface 50 defining an outer diameter (D1) and a seal
12 therearound intermediate the opening 28 and the transverse portion
24 for cooperating with the canister 14 (FIG. 5) to form a proper
seal between the cartridge 10 and the canister 14 (FIG. 5).
[0030] The seal 12 is preferably comprised of a thermoplastic elastomer,
most preferably SANTOPRENE.RTM., which is available from Advanced
Elastomer Systems, L.L.P., located in the U.S. in Akron, Ohio and
Auburn Hills, Mich. The SANTOPRENE.RTM. product is superior to today's
polypropylene flanges, or seals, insofar as the SANTOPRENE.RTM.
provides a higher heat resistance to welding and a greater flexibility
which allows the seal 54 to deflect but still maintain a proper
seal. Specifically, SANTOPRENE.RTM. offers a constant service temperature
range (-81.degree. F. to 275.degree. F.) with no cracking or tackiness;
has excellent resistance to cut growth while flexing; has high tear
strength and superior resistance to fatigue; and a wide range of
flexibility, among other favorable characteristics.
[0031] As best shown in FIGS. 2 and 3 the seal 12 includes a continuous
body 56 preferably annular in shape, having opposing first and
second longitudinal side edges 58 and 60 and an inner surface 62
defining an inner diameter (D2). The seal 12 further includes a
lip 66 extending outwardly from the body 56. Preferably, the lip
66 extends outwardly from one of the side edges 58 and in a direction
towards the opposite side edge 60 such that a cross-section of the
seal 12 reveals a substantially v-shape. The lip 66 of the seal
12 is adapted to resiliently fit, by a friction or interference
fit, within the canister 14 (FIG. 5) of an air conditioning or refrigeration
system (not shown). This resilience, or flexibility, of the lip
66 allows for compensations for the variations in diameters of canisters
14 such that a cartridge 10 can be sized from one mold (not shown).
The seal 12 preferably is removably detachable from the cartridge
10 (FIG. 1). Notably, the inner diameter (D2) of the seal 12 is
less than the outer diameter (D1) (FIG. 1) of the cartridge 10 (FIG.
1) in order to create a stretch fit for the seal 12 around the outer
surface 50 (FIG. 1) of the outer wall portion 22 (FIG. 1).
[0032] As shown in FIG. 4 the seal 12 preferably is positioned
around the outer wall portion 22 of the cartridge 10 such that the
body 56 is situated adjacent the outer surface 50 and the lip 66
extends outwardly from the body 56 and away from the cartridge 10
in a direction towards the opening 28 thereof. The artisan will
appreciate that the seal 12 can comprise a multiplicity of various
dimensions and still conform to the cup 16 such that it is secured
therearound.
[0033] As best shown in FIG. 4 the outer wall portion 22 includes
a seal stop 68 which protrudes outwardly from the outer surface
50 of the outer wall portion 22 intermediate the opening 28 and
the transverse portion 24 for limiting axial movement of the seal
12 along the outer surface 50. The seal 12 preferably is positioned
intermediate the seal stop 68 and the opening 28.
[0034] In FIGS. 1 and 4 a cap 70 conforms to the circular shape
of the cup 16 and has a planar portion 72 having an outer and inner
circumference defining an aperture for receiving the inner wall
portion 20 when the cap 70 is received in the chamber 26. The cap
70 further is provided with a peripheral flanged portion 80 extending
transversely from the outer circumference of the planar portion
72 and having a continuous edge portion 82 which cooperates with
the outer wall portion 22 to retain the cap 70 to the cup 16. A
central flanged portion 84 extends transversely from the inner circumference
of the planar portion 72 which cooperates with the inner wall portion
20 to further aid in retaining the cap 70. The artisan will appreciate
that the cap 70 can comprise a multiplicity of various features
and dimensions and still conform to the cup 16 such that it is secured
thereto.
[0035] Additionally, as best shown in FIG. 4 an inner surface
86 of the outer wall portion 22 of the cup 70 may include a plurality
of inner surface protrusions 88 including, but not limited to, ribs,
nibs, beads, bumps or other equivalent protrusions projecting radially
inwardly from the outer wall portion 22 which engage and retain
the cap 70 in one of a number of axially spaced positions.
[0036] As shown in FIGS. 1 and 4 the transverse portion 24 of
the cup 16 (FIG. 4) and the cap 70 (FIG. 1) are each perforated
with a number of ports 90 or perforations so that the cap 70 (FIG.
1) and the transverse portion 24 (FIG. 4) are each permeable to
the air or fluid (not shown) to be dried. As shown in FIG. 1 the
cap 70 is provided with a multiplicity of oblong, petal shaped ports
90 generally disposed with their major axes radially extending from
the center tube 44 (FIG. 4) toward the outer circumference of the
cap 70. The ports 90 of the cap 70 and transverse portion 24 (FIG.
4) preferably are arranged in one concentric annular row. The precise
arrangement and shapes of the ports 90 is not critical to the operation
of the desiccant cartridge 10 as long as the desiccant 30 (FIG.
4) remains contained and air or fluid (not shown) is allowed to
enter the cartridge 10 interact evenly with the desiccant 30 (FIG.
4), and exit from the cartridge 10.
[0037] As shown in FIG. 4 plies of a permeable lining material
91 and 92 such as felted polyester or gauze can be placed inside
the chamber 26 near the transverse portion 24 and the cap 70 to
trap the desiccant 30 in the cartridge 10. The plies 91 92 must
be permeable to the air or fluid (not shown) to be dried but impermeable
to the particulate desiccant 30.
[0038] As best seen in FIG. 4 to assemble the desiccant cartridge
10 the first ply of permeable lining material 91 is inserted by
sliding it down the inner wall portion 20 until positioned adjacent
the transverse portion 24. Then, the required amount of desiccant
30 is poured therein. The desiccant material 30 comprises beads
that are commercially available from Universal Oil Products under
the XH7 designation. A dye wafer 32 (FIG. 5) also may be placed
into the chamber 26. Once the desiccant 30 is charged, the second
ply of the permeable lining material 92 can be slid down the inner
wall portion 20 against the desiccant 30. The cap 70 is then inserted
into the chamber 26 and urged downwardly toward the transverse portion
24 until it abuts against the charged desiccant 30.
[0039] The seal 12 preferably comprising SANTOPRENE.RTM., can
be stretch fit around the outer wall portion 22 of the cartridge
10 any time during assembly, preferably, prior to insertion of the
cartridge 10 into the canister 14 (FIG. 5). The seal 12 is positioned
intermediate the opening 28 and the transverse portion 24 and adjacent
the seal stop 68. The body 56 of the seal 12 is situated adjacent
the outer surface 50 and the lip 66 extends outwardly from the body
56 and away from the cartridge 10 preferably, in a direction towards
the opening 28.
[0040] Once the desiccant cartridge 10 is assembled, it is inserted
into the canister 14 as shown in FIG. 5. The cartridge 10 may be
vibrator or bowl fed to a robotic arm (not shown) for automatic
installation into the canister 14. The seal 12 cooperates with an
inner surface 94 of the canister 14 thereby forming a proper seal
therebetween while the second end 38 of the tube 44 communicates
with a mounting flange 96 that is spaced above a bottom wall 98
of the canister 14 to support the cartridge 10. When the lid 48
is placed onto the canister 14 the center tube 44 aligns with an
outlet port 102 such that the first end 36 of the tube 44 is in
communication therewith. The desiccant cartridge 10 now is properly
secured within the canister 14 such that it does not move up and
down or allow air or fluid (not shown) to leak.
[0041] 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. |