U.S. patent application number 09/802063 was filed with the patent office on 2001-10-04 for filter cartridge and condenser.
Invention is credited to Bernini, Michele.
Application Number | 20010025511 09/802063 |
Document ID | / |
Family ID | 26056138 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010025511 |
Kind Code |
A1 |
Bernini, Michele |
October 4, 2001 |
Filter cartridge and condenser
Abstract
A filter cartridge F in a condenser K for an automobile
air-conditioning system comprises a permeable housing 1 containing
a desiccant charge, said housing being inserted into a header pipe
8 of said condenser which header pipe is closed by a plug S being
part of said filter cartridge F. In a condenser K being equipped
with a filter cartridge F in header tube 8 which is closed by a
plug S said plug is made from plastic material or light metal and
is part of said filter cartridge F to fulfil a dual function,
namely to seal the header tube and to position the cartridge.
Inventors: |
Bernini, Michele;
(Scarzara(Parma), IT) |
Correspondence
Address: |
ARMSTRONG, WESTERMAN, HATTORI,
MCLELAND & NAUGHTON LLP
LAW & FINANCE BUILDING
429 FOURTH AVE, SUITE 707
PITTSBURGH
PA
15222
US
|
Family ID: |
26056138 |
Appl. No.: |
09/802063 |
Filed: |
March 8, 2001 |
Current U.S.
Class: |
62/531 |
Current CPC
Class: |
F25B 2400/162 20130101;
B01D 5/0072 20130101; F25B 39/04 20130101; F25B 43/003 20130101;
F25B 2339/0441 20130101 |
Class at
Publication: |
62/531 |
International
Class: |
F25B 043/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 9, 2000 |
DE |
200 04 438.9 |
Nov 10, 2000 |
EP |
00124652.9 |
Claims
1. Filter cartridge in a condenser, particularly for an automobile
air conditioning system, comprising a permeable housing and at
least one desiccant charge, the housing being dimensioned for
insertion through an insertion opening into a header pipe of said
condenser, said insertion opening being closed by a plug
characterised in that said plug is part of said filter
cartridge.
2. Second filter cartridge as in claim 1, characterised in that
said housing of the filter cartridge has an longitudinal spacer,
and that said plug is provided at a free end of said spacer.
3. Filter cartridge as in claim 2, characterised in that said
spacer is made from plastic material or light metal, and that said
plug is also made from plastic material or light metal and is
detachably or unitarily provided at said spacer.
4. Filter cartridge as in claim 2, characterised in that said
spacer is separable from said housing at its end opposite to said
plug, and that said spacer is yieldably supported within said
housing preferably by means of a spring.
5. Filter cartridge as in claim 1, characterised in that said plug
is provided at a lower end of said housing of said filter
cartridge.
6. Filter cartridge as in claim 1, characterised In that said plug
is a generally cylindrical body made from plastic material or light
metal comprising at least one circumferential groove for a sealing
element and an axial supporting structure for a securing element,
e.g. a C-ring.
7. Filter cartridge as in claim 1, characterised in that an outer
gripping flap is formed at said plug.
8. Filter cartridge as in claim 1, characterised in that a socket
and an access channel for a sensor and/or a charging valve is
provided within said plug, said socket removably receiving a sensor
and/or filling valve component.
9. Filter cartridge as in at least one of the preceding claims,
characterised in that said housing is separated into an inlet
filter zone and an outlet filter zone both separated from another
by an outer seating lip or an annular flange, and that in said
outlet filter zone a filter fabric element with fine pores is
provided, while in said inlet filter zone micro-bores are formed in
the wall of said housing.
10. Filter cartridge as in claim 9, characterised in that said
micro-bores are formed by needle-shaped inserts in an injection
mold for forming said housing.
11. Filter cartridge as in claim 1, characterised in that said
housing defines an inlet or outlet filter structure for a fluid,
said housing being connected at one end to said plug and at its
other end to a fluid permeable bag receiving said desiccant
charge.
12. Condenser, particularly for an automobile air conditioning
system, comprising a header tube having an insertion opening, a
filter cartridge removably positioned within said header pipe and
containing a desiccant, and comprising a plug sealingly closing
said insertion opening characterised in that said plug is made from
plastic material or light metal and is part of said filter
cartridge.
13. Condenser as in claim 12, characterised in that said plug of
said filter cartridge is secured within the upwardly facing or
downwardly facing insertion opening by means of a securing element
engaging into the wall of said insertion opening and abutting
against an outer supporting element of said plug.
14. Condenser as in claim 13, characterised in that said securing
element is a Seeger-ring seated in a groove of said insertion
opening.
15. Condenser as in claim 13, characterised in that said securing
element is a clip or locking pin extending from outside through the
wall of said header pipe.
16. Condenser as in claim 13, characterised in that said supporting
element is a lateral shaft formed within plug for receiving said
clip or locking pin.
17. Condenser as in claim 15 or 16, characterised in that said clip
or locking pin has an insertion end and a holding end, said holding
end being positively abutting the outer side of said header pipe,
said insertion end where protruding beyond said header pipe
receiving an additional safety element blocking said clip or
locking pin against being pulled out.
18. Condenser as in claim 15, characterised in that said clip or
locking pin is made from metal or plastic material.
19. Condenser as in claim 17, characterised in that said clip or
locking pin is formed as an elastic tongue with a width
perpendicularly to the axis of said header pipe smaller than the
width of said lateral shaft is said plug and having in width
direction an arc-shaped bend such that the inserted clip or locking
pin is pre-loaded in bending direction in openings of the wall of
said header pipe and within said lateral shaft.
20. Condenser as in claim 13, characterised in that said securing
element is part of a bayonet closure, comprising at least one
safety function guiding curve and at least one engaging element,
said guiding curve either being formed in the wall of said header
pipe or said plug and the engaging element being formed either at
said plug or at the wall of said header pipe, respectively.
21. Condenser as in claim 13, characterised in that said securing
element is a C-ring or Seeger-ring seated in a groove of said
header pipe with an axial safety function clearance.
Description
[0001] The invention relates to a filter cartridge according to the
preamble part of claim 1 as well as to a condenser according to the
preamble part of claim 13.
[0002] A filter cartridge as known from EP-A-0 669 506 is provided
within a collecting tube or header pipe of the condenser and is
sealed and positioned by means of a metallic plug screwed into the
insertion opening of said tube. Since said filter cartridge is
supported in its operating position under a certain axial load, it
simultaneously is backed up by the plug. This is a conventional
structural principle of filter cartridge equipped condensers. There
is a relatively precisely machined and tight thread connection
provided between the plug and the insertion opening This is
expensive. However, since the condenser or the condenser housing
during manufacturing, e.g. during soldering, is thermally loaded
relatively strong, without the filter cartridge positioned within
the header pipe, deformations of the insertion opening might occur
so that the plug cannot be screwed in easily later and might not be
sufficiently tight. Moreover, further irregularities between the
plug and the insertion opening at the threaded connection might
result from unavoidable temperature variations and corrosion
effects and varying mechanical loads during operation of the
condenser. This makes its particularly complicated to remove the
plug for a change of the filter cartridge after a long duration use
of the condenser. Even if then the plug can be removed in a
troublesome way it often cannot be used a second time. Also a new
plug then does not fit properly into the insertion opening. This
problem might cause expensive and time-consuming remachining
efforts.
[0003] It is a task of the invention to provide a filter cartridge
as well as a condenser with a filter cartridge, as mentioned above,
which are structurally simplified and which allow assembly and
disassembly and an exchange of the filter cartridge in a
comfortable way.
[0004] Said task can be achieved by the features contained in claim
1 and in view to the condenser by the features of claim 11.
[0005] Since the plug is a part of the filter cartridge a separate
manufacturing of a proper plug is avoided. The plug is mounted in
the insertion opening first when also the filter cartridge is
inserted. The plug then hermetically seals the insertion opening
against the outer environment. Simultaneously the plug takes care
of the correct positioning of the cartridge. The plug does not need
to be screwed-in so that a threaded connection sensitive to
deformation is avoided. The plug, instead, can be pressed in
axially and/or secured in position by simple fastening
elements.
[0006] The dual function plug made from plastic material as or
light metal forming a part of the filter cartridge offers the
possibility of a simple and comfortable assembly of the cartridge
into the condenser, since the plug is introduced or pressed into
the header pipe together with the filter cartridge until the filter
cartridge and the plug reach their respective and correct
positions. The plug, particularly if it is made from plastic
material, is able to adapt itself to the shape of the insertion
opening, even if the insertion opening should have been de-formed
during the thermal treatment of the condenser or condenser housing
or de-forms during operation. The necessary tightness is assured
permanently. Removal, e.g. for exchanging the filter cartridge, of
the plug can be carried out comfortably. The plug seals the
collector tube and positions the cartridge.
[0007] As the filter cartridge has to be secured in the long header
pipe of the condenser in its correct operating position, it is
expedient, to provide the filter cartridge with a spacer and to
provide the plug directly at said spacer.
[0008] Said plug can be connected detachably with the spacer or can
be formed unitary with the spacer e.g. from plastic material.
[0009] Expediently the plastic or light metal spacer comprising the
plug is detachably connected to the housing of the filter
cartridge.
[0010] In order to achieve a correct positioning of the filter
cartridge it is of advantage to support the spacer in the housing
of the filter cartridge in a yieldable fashion (to axially pre-load
the cartridge).
[0011] In an alternative embodiment the plug is provided at the
lower end of the housing of the filter cartridge. In this case this
is a filter cartridge which is inserted through a lower insertion
opening into the header pipe of the condenser and which is
positioned by the plug.
[0012] In view to manufacturing it is of advantage if the plug is a
cylindrical body of plastic material or light metal with in-built
sealing grooves and a supporting element like a surface for a
securing element. Said plug is brought into its sealing position
essentially only by axially pressing it into the insertion opening.
Sealings provided in said grooves, preferably several O-rings,
assure the necessary tightness. The supporting surface bears
against the securing element such that the plug and by means of the
plug also the filter cartridge remain properly positioned.
[0013] For an easy removal of the filter cartridge a gripping flap
can be formed on the plug.
[0014] Alternatively or additionally a seat socket and a channel
for a sensor and/or a charging valve can be formed in said plug,
said socket receiving said sensor and/or charging valve.
[0015] The housing of the filter cartridge is equipped in the
outlet zone with filter material having small pores the sizes of
which suffice to retain even the smallest particles. To the
contrary, the inlet zone is provided with micro-bores assuring a
strong and uniform flow of the refrigerant towards the desiccant
charge within the housing. Said micro-bores can be produced far
less expensively in an injection mold than to mold a conventional
cage-like housing portion. Said micro-bores can be formed by
needle-like inserts in the injection mold and during the injection
process of the housing. Expediently said needle-like inserts extend
perpendicular to the mold separation plane such that they can be
positioned stationarily within the form and are pulled out from the
product when the mold halves are separated.
[0016] In another embodiment, the housing of the cartridge directly
is connected to the plug. The housing has openings covered by
molecular sieves, and may be provided with a separation sealing lip
or O-ring. The desiccant charge is received in a flexible fabric or
sieve bag connected to the housing and in flow connection with the
interior of the housing.
[0017] Said filter cartridge can be assembled easily into the
condenser and can be changed at any time through the insertion
opening, irrespective where said opening is located. The plug as a
part of the filter cartridge is provided at the respective end of
the filter cartridge, and consists expediently of plastic material
or light metal. The plug is positioned in the insertion opening by
an essential axial pushing movement and does not need a threaded
connection. The plug maintains its position with the help of the
securing element positively engaging into the inner wall of the
insertion opening. Said securing element hinders the plug to
inadvertently move out from the insertion opening. Said securing
element can be a Seeger-ring or C-ring which is available in
different sizes and with low costs. Seeger-rings are easy to mount
and remove and generate the necessary holding force for the plug in
a positive fashion.
[0018] In another embodiment said securing element may be a clip or
a locking pin extending from outside through said header pipe and
said plug. Said securing element can be removed and mounted
comfortably and establish a high degree of safety against
accidental removable. Said clip or locking pin may be inserted into
a lateral shaft provided in the plug such that the plug neither can
be pressed inwardly nor can escape from the header pipe.
Expediently said clip or locking pin has an insertion end and at
its opposite end a holding end. Said holding end positively is
supported at the outer side of the header pipe, while another
safety element can be inserted into the protruding insertion end.
Said safety element may be a spring ring or a spring clip or even a
lock. The clip or locking pin can be made of metal or plastic
material.
[0019] Expediently said clip is formed like an elastic tongue which
is flat in lateral direction and has a width smaller than the width
of the shaft in the plug and is formed with a bend such that it can
be held under preload when inserted to more safely secure the plug
in its position.
[0020] Another embodiment uses a bayonet system for securing the
plug in its position. A guiding curve can be provided, e.g. at the
inner side of the wall of the header pipe for an engaging element
of the plug. In case that said guiding curve is U-shaped the
bayonet provides a further safety aspect, because the plug has to
be first pressed in for the removing rotation of the bayonet
design. However, the plug only can be pressed in if there is no
significant pressure within said header pipe. As long as there is
residual pressure, the bayonet closure cannot be opened until the
pressure has been vented in the conventional way. This protects the
car mechanic or the car owner when trying to exchange the filter
cartridge with the system under pressure.
[0021] Even with a securing ring, e.g. a C-ring, said safety aspect
can be provided, assuring that the cartridge cannot be removed
inadvertently as long as the system pressure is too high. For that
function the header pipe may be formed with an inclined shoulder
supporting the plug, and with an axial clearance in the seat groove
for the C-ring. An outer counterstay shoulder of the groove is
firmly contacted by the C-ring in case of considerable system
pressure, hindering to remove the C-ring without first relieving
the pressure.
[0022] Embodiments of the invention will be explained with the help
of the drawing. In the drawing is;
[0023] FIG. 1 a longitudinal section of a part of a condenser with
inserted filter cartridge,
[0024] FIG. 2 a part as emphasised in FIG. 1 by circle, in enlarged
scale and partial in sectional view,
[0025] FIG. 3 a front view of another embodiment of a filter
cartridge,
[0026] FIG. 4 a detail belonging to FIG. 3,
[0027] FIG. 5 a part of a further embodiment of a filter cartridge
in its operating position in a header pipe of a condenser,
[0028] FIGS. 6, 7 & 8 three interrelated sections of another
embodiment.
[0029] FIG. 9 a safety locking feature of the plug, and
[0030] FIG. 10 another embodiment of a cartridge/plug assembly.
[0031] FIG. 1 shows a header pipe 8, e.g. a vertical header pipe,
at one end of a condenser K, in a longitudinal section. In said
header pipe 8 a filter cartridge F is positioned in its operating
position. Said filter cartridge F contains inter alia a charge of a
desiccant serving to extract water from the refrigerant circulating
through the condenser water and also to retain particles contained
in the refrigerant and a filter structure. Said filter cartridge F
has a generally tube-shaped housing 1 with a permeable inlet filter
zone Z and a permeable outlet filter zone A. In-between a ring
flange 4 carrying at least one sealing element 5 serves as a
separation wall co-operating with the header tube 8. Said housing 1
may have integrated spacing elements 2. Moreover, at the upper end
of housing 1 a spacer 3, e.g. equipped with a spring element, is
provided abutting at a cap 17 e.g. soldered into header pipe 8.
[0032] In this embodiment filter cartridge F is inserted into the
header pipe from above through a downwardly facing insertion
opening E. The filter cartridge is positioned in header pipe 8 by a
plug S closing the header pipe insertion opening E. Plug S is made
from plastic material or light metal and is part of the filter
cartridge F. Plug S is pressed essentially linearly into said
insertion opening E and is sealing with the help of O-rings 5. Plug
S maintains its position thanks to a securing element 7 which
positively is fixed in the mouth of insertion opening E. A gripping
flap 6 can be formed a plug S.
[0033] Housing 1 has a plurality of micro-bores M in its inlet
filter zone Z. Outlet openings 15 of the housing 1 in said outlet
filter zone A even are covered by filter material 16 having very
fine pores. The refrigerant, mainly in its liquid phase, enters
header tube 8, and enters housing 1 through said micro-bores M.
From the interior of housing 1 and after having passed at least the
desiccant the refrigerant exits through the filter material 16 and
leaves said header pipe 8 e.g. through a side opening 14.
[0034] FIG. 5 shows how securing element 7 is inserted into a
groove 19 formed within insertion opening E. It abuts against a
supporting element 29 e.g. a surface of plug S. Plug S has
circumferential grooves 18 for O-rings 5.
[0035] Said micro-bores M expediently are formed during injection
molding housing 1 and by means of needle-equipped inserts N (FIG.
3) in the injection mold Q. In case that said needles of said
inserts N are oriented perpendicular to the separation plane of the
injection mold the final injection moulded product can be removed
easily. This is simpler in view to production and the design of the
injection mold than to form said inlet zone Z as a cage-like
structure Said plug S in FIG. 1 is either formed unitarily with
housing 1 or is fixed thereto.
[0036] In FIG. 2A the securing element 7 is a bayonet closure
having at least one engagement element 34 e.g. provided at plug S
and at least one guiding curve 35 provided e.g. in the inner wall
of header pipe 8. Said bayonet closure 33 provides an additional
safety aspect, since it needs for removal to first press plug S
into header pipe 8, in order to move engagement element 34 in the
U-shaped guiding curve 35. Even relatively low system pressure
within header pipe 8 inhibits said inward motion of plug S and
first has to be relieved for protecting the mechanic or the
environment against pressurised cooling agent from the system.
[0037] In FIG. 28 said securing element 7 is a clip, splint or
locking pin 36 seated within channels 37, 38 provided in plug S and
within the wall of header tube 8.
[0038] The filter cartridge F as shown in FIG. 3 is intended to be
inserted into a header pipe (not shown in FIG. 3) from the upper
end. The inlet zone Z of housing 1 is defined by a plurality of
micro-bores M. Said inlet zone Z is separated from the outlet zone
A by a sealing lip 4'. In order to position the housing 1 deep
enough essentially within the liquid phase of the refrigerant in
header pipe 8, a spacer D is connected to the housing 1. Said
spacer D carries plug S at its end opposite to housing 1.
Sidewardly oriented wings 21 on spacer D serve to center it within
the header tube 8. Housing 1 is formed with an upper opening and an
annular inner flange 26. A lower flange 24 of spacer D can be
forced by resilient deformation past said annular flange 26 in
order to connect the spacer D and the housing 1, e.g. after
inserting the desiccant-charge.
[0039] According to FIG. 4 the plug S is designed with a lower
threaded blind bore 22 into which a threaded protrusion 23 of
spacer D is screwed. The lower flange 24 is positioned at spacer D
by means of a locking nut 25.
[0040] In the embodiment of FIG. 5 the filter cartridge F is
provided, similarly as in FIG. 3, with a lower housing 1 and an
upper spacer D. Spacer D rests with its flange 24 on a compression
spring 30 supported by a lid 31 within housing 1, such that housing
1 is pre-loaded downwardly in its working position, once spacer D
and plug S are correctly positioned by securing element 7. Plug S
is unitarily provided at the upper end of spacer D and is made from
the same plastic material or light metal as the spacer. The plug is
provided in an upper insertion opening E of header pipe 8 and is
secured in its position without a threaded connection by securing
element 7, e.g. a Seeger-ring, seated in a groove 19 in the mouth
of insertion opening E. Securing element 7 abuts supporting surface
29 of plug S. In this embodiment plug S is provided with a socket
27 receiving a sensor and/or a charging valve 28. A channel 32
leads from socket 27 downwardly and into the header pipe 8.
[0041] During assembly of the filter cartridge F into header pipe 8
of the condenser K first the filter cartridge F is inserted until
plug S has reached the proper position. Then securing element 7 is
inserted. In order to change the filter cartridge the securing
element 7 is removed and the filter cartridge then can be pulled
out, e.g. by means of gripping flap 6. In FIGS. 6, 7 and 8 securing
element 7 is clip 36 of a special design inserted into openings 38
in the wall of the header pipe 8 and in a lateral shaft 39 formed
within plug S and defining said supporting element 29. Both ends
40, 41 of said clip 36 protrude beyond the wall of header pipe 8.
Said clip 36 can be made from metal or plastic and is designed as a
flat, elastic tongue in FIG. 6 having, according to the view of
FIG. 8, an arc-shaped bend 43. Since lateral shaft 39 is broader
perpendicular to the axis of header pipe 8 than the width of clip
36, but the bend 43 is stronger than the width of the lateral shaft
39 the inserted clip 36 is pre-loaded. It is supported by said
pre-load within openings 38 and at the wall of lateral shaft 39.
Holding end 40, e.g. a sidewards bent end portion, abuts the outer
side of header pipe 8. Insertion end 41 protruding at the opposite
side receives safety element 42 (e.g. a spring ring or a spring
clip as shown in FIG. 7) or even a lock preventing that clip 36 can
be pulled out accidentally.
[0042] Said clip system can be manufactured with low cost, because
e.g. the openings in the header pipe as well as the lateral shaft
in the plug can be formed by pressing or injection molding.
[0043] In FIG. 9 the safety feature already mentioned is provided
for securing element 7 formed as a C-ring seated by radial
expansion in groove 19 of header pipe 8 Between groove 19 and said
C-ring an axial clearance 50 is provided. The upper shoulder 44 of
groove 19 serves as a counterstay surface for C-ring 7 as long as
considerable system pressure presses the plug S upwardly. This
hinders removal of the C-ring 7 and need to relieve the system
pressure and then to first move the plug S downwardly to clear the
C-ring 7 in groove 19. The downward movement of plug S is limited
by an internal inclined shoulder 45 of header pipe 8.
[0044] In FIG. 10 the plug S directly is connected to the housing
1, openings 46 of which may be covered by a molecular sieve 47.
Housing 1 has a circumferential separation lip 4'. At the free end
of housing 1 a flexible (fabric or sieve material) bag 48 is fixed
which contains the desiccant charge.
* * * * *