CA1139238A

CA1139238A - Liquid filter and filter element

Info

Publication number: CA1139238A
Application number: CA000342919A
Authority: CA
Inventors: Howard W. Morgan, Jr.
Original assignee: Filter Specialists Inc
Current assignee: Pall Filter Specialists Inc
Priority date: 1979-01-02
Filing date: 1980-01-02
Publication date: 1983-01-11
Also published as: GB2113110A; GB2042359A; GB2042359B; DE3000013C2; JPS55159818A; DE3000013A1; JPS6234405B2; GB2113110B

Abstract

AN IMPROVED LIQUID FILTER AND FILTER ELEMENT

Abstract of the Disclosure A liquid filter having a housing which includes a chamber enclosed by a cap. A filter is positioned within the chamber and includes a flange which makes a hermetic seal with the housing.

Description

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Summary of the Invention This invention relates to a filter having an improved filter element.
The filter of this invention includes a housing having a side wall which defines a chamber. ~n opening into the chamber is formed in the housing. A cap spans the chamber opening. A filter element, such as a screen or bag or a bag and screen in combination, is fitted into the housing and engages the housing in such a manner so as to form a liquid seal between the element at its opening and the housing. The filter element can be provided with stops, such as a cam lock, which enables the element to be interlocked with the filter housing.
Accordingly, it is an object of this invention to provide a liquid filter having an improved filter bag.
Another object of this invention is to provide a liquid filter having a reticulated filter element which is fitted and independently retained within the filter housing.
Another object of this invention is to provide a liquid filter having a filter bag which forms a hermetic seal about the bag entrance with the filter housing.
Still another object of this invention is to provide a liquid filter bag having a wall part formed of a flexible liquid pervious material and a ring part formed of a shape-retaining liquid impervious material which is joined to the wall part at an internal lip portion.

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Other objects of this invention will become appar~nt upon a reading of the invention's description.
Brief Description_of the_Drawin~s Figure 1 illustrates one embodiment of this invention with the filter shown in vertical sectional form.
Figure 2 is a fragmentary sectional view showing the filter bag of Figure 1 being inserted into the filter housing.
Figure 3 is a fragmentary sectional view showing the filter bag of Figure 1 seated in the filter hollsing.
Figure 4 is a fragmentary sectional view showing the filter of Figure 1 being removed from the filter housing.
Figure 5 is a cross sectional view of the filter taken along line 5-5 of Figure 1 with portions of the filter bag and reticulated basket broken away for purposes of illustration.
Figure 6 is a view of that portion of Figure 5 en-closed within broken line circle 6 showing the reticulated basket of the filter in broken lines in proper position to be removed from the filter housing.
Figure 7 is a fragmentary sectional view of a modified embodiment of the filter showing a filter bag bein~ fitted into the filter housing.
Figure 8 is a fragmentary sectional view showing the filter embodiment of Figure 7 with the filter bag seated therein.
Figure 9 i8 a fragmentary sectional view showing still another embodiment of the filter with the filter bag seated in the filter housing.
Figure 10 illustrates another embodiment of this invention with the filter shown in vertical sectional form.

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Figure 11 is a fragmentary sectional view taken along line 11-11 of Figure 10.
Figure 12 is a fragmentary perspective view of the filter housing and filter screen locking components shown in separated form.
Description of the Preferred Embodiments The preferred embodiments illustrated are not intended to be exhaustive or to limit the invention to the precise forms disclosed. They are chosen and described in order to best explain the principles of the invention and its application and practical use to thereby enable others skilled in the art to best utilize the invention.
Filter 10, shown in Figures 1-6, includes a housing 12 having a side wall 14 and a bottom wall 16 defining an internal chamber 17. An opening 18 defined by side wall end edge 20 into chamber 17 is formed in housing 12 and is oppocitely located from bottom wall 16 of the housing. A cap 22 spans opening 18 in housing 12. Cap 22 rests upon side wall end edge 20 and is retained in position by a plurality of removable threaded hold-down members 24. An O-ring 26 is placed in compression between cap 22 and housing 12 so as to provide a liquid seal between the cap and housing.
Cap 22 includes an inlet port 28 and bottom wall 16 of housing 12 includes an outlet port 30 by which liquid can flow through filter 10. Legs 32 are connected to housing bottom wall 16 for the purpose of maintaining filter 10 in an upright position during use. Filter 10 thus far described is of a standard, commercially available construction.

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l llousincJ side wall 14 carries an annular shoulder 34 which is inset or s~aced frorn end edge 20 of the housing.
Shoulder 34 is interrupted at two diametrically spaced locations by slots 36. An annular flan~t-~ 38 is also carried by side wall 14 of the hous.illg. ~`lanc~e 38 is sp~ced from shoulder 34 and i.s located be~tween the shoulder and end edge 20 of housing 12.
A basket 40~having a roticulated wall 42 is fitted with-in housiny 12. Basket 40 is for the purpose o~ ~supporting a filter bag 44 and thus is formed of a rigid .shape-r2taining construction. An outturned marginal edge or annular flange 46 is formed at the opening into basket 40. ~he outer diameter of basket flange 46 exceeds the inner diameter of housing shoulder 34, but is less than the inner diameter of housing flange 38 to permit tl-e basket to be removahly inserted into the housing through its openiny 18, with flange 46 overlying and resting upon shoulder 34. A pair of diametrically located stops 48 are connectecd to basket wall 42 in a spacet~ relationship bc~ow b~sket flange 46.
Stops 48 are si~ed sc> as to pass with clearance through slots 36 in housing shoulder 34 as seen in broken lines in fig. 6 when the basket is beiny first :insertt-~d into the housiny. Once stops L~8 }~ave p~lssecl t~lrough slots 36 and are locatcd below the inncr t;~t.1ge 35 of shouJ.t~t-~r 34, the basket can be rotated relative to htjusin~3 l~ to cause the stops to be positioned under an unintorruptetl portion of the shouldcr, as illustrated in figs. l and 5. The spatinc3 between stops ~8 and overlyiny ~as};et flanye 46 slightly exceeds the thickness of housing shouJ.der 34 so that ~hc~ll tl-le stops are posi~oncr~ ullder an uninterrupted ~139;~3~

portion of shoulder 34, basket 40 will be prevented from being withdrawn any appreciable dis~ance from the filter housing.
Filter bag 44 includes a wall part 50 which is formed of a flexible, liquid pervious material, such as interwoven nylon, cotton or wool, and ~ ring part 52 which is formed of a flexible shape-retaining material, such as nylon or poly-propylene. Ring part 52 defines the opening 54 into bag 44 and is attached at its annular internal lip 53 to wall part 50, such as by sewing or heat sealing. Bag ring part 52 includes an out-turned flange 56 which terminates into a tapering lip 58. The diameter across the opening 54 into bag 44 as measured diametrically across the outer edge of lip 58 just slightly exceeds the inner diameter of side wall 14 of the filter housing as measured above housing shoulder 34 between the shoulder and overlying flange 38.
With filter cap 22 removed and basket 40 supported upon shoulder 34 at its flange 46, bag 44 is inserted into the basket with lip 58 of the bag being flexed first upwardly and then around protruding flange 38 of the housing, as illustrated ~o in Figures 2 and 3. Flange 56 of bag 44 fits between flange 38 and shoulder 46 of basket 40 with the outer edge of lip 58 of the flange making peripheral liquid sealing contact with side wall 14 of the housing. Liquid flow as indicated by arrows 60 in Figure 1 will cause flange 56 of bag 44 to press downwardly against flange 46 of basket 40, thereby firmly positioning the basket within housing 12 so that the liquid first enters the interior of bag 44 from filler inlet port 28 and ~ , 1~39231~
l thereafter passes thr~ugh pervious rilterinq wall part 50 of the bag and openings 62 in bas~et 40 and out out~et port 30.
Ring part 52 of bag 44 include~ a pair of tabs 64 whicl- arc integrally formcd to flallye 56 of the bag.
Tabs 64 when pulled outwardly as shown by arrc>w 57 in ~ig.
4 with cap 22 removed from the filter cause 1.ange 56 to be flexed and cammed inwardly and pulled from engagement with housing flange 38 to rele~e the bag from the f$1ter for purpose of replacement or cleaning. Wall part 50 of the b~g will usually adhere to ba~ket 40 duriny initial efforts to remove it from the filter. This bag-~a~ket adherence causes the ba~ket to move toward opening 18 in housing 12 until basket stops 48 engage the inncr edge 35 of housing shoulder 34 where f~rther outward movement of the basket is prev~nted as bag 44 is pulled from the basket.
In figs. 7 and 8 a modiied orm of the filt~r ~hown in fic3~ 6 i.s illu~trated. In this embodimcnt, hou~ing 12 is modified by the elimination of flanye 38 and the introduction of an annular interio~ groove 66 between shoulder 34 and end edge 20 o the housing. lrhe diameter of housing side wall 14 at the place of maximum depth of groove 66 is slightly les~ than the outer diameter of ba~ 44 a~ me~sured across the outer edge of it~ lip 58.
Ring part 52 of bag 44 i9 wedged into housln~ 12 ~ith lip 58 bein~ flexed outwardly, ~s seen in fig. 7, until groove 66 of the housiny i~ reached. Lip 58 then ~pring~
i.nto groove 66 to interlock the bay wiOI the filter hou~ing, as seen in fi.g. 8, with lan~Je 56 of the bac3 overlyin~ and p.referably contacting ba~ket f1.ancJe 46. In thi~ em~odiment, 11392;~

the compressive ~it of bag lip 58 into housing gxoove 66 forms a liquid seal between the bag and the housing. The operation of the filter in the embodiment shown in Figures 7 and 8 is similar to the operation of the embodiment illustrated in Figures 1-6. Bag 44 shown in Figures 7 and 8 can be removed from basket 40 by an outward pull upon tabs 64.
In Figure 9 another embodiment of this invention is illustrated. In this embodiment side wall 14 of housing 12 is provided with a straight internal surface between shoulders 34 and end edge 20. The inner diameter of side wall 14 between shoulder 34 and end edge 20 is less than the outer diameter of bag lip 58. Ring part 52 of bag 44 is wedged into housing 12 with lip 58 contacting housing side wall 14 above shoulder 34. This wedge fit between bag 44 and housing 12 not only forms an annular peripheral liquid seal between lip 58 of the bag and side wall 14 of housing 12, but also causes flange 56 of the bag to overlie and preferably contact out-turned flange 46 of basket 40 to urge the basket into contact with housing shoulder 34. When cap 22 of the filter has been secured to housing 12 over its opening 18, liquid flow through the filter will cause pressure to be brought against the outer surface of bag lip 58 to enhance the seal between the lip and side wall 14 of filter housing 12. Bag 44 in the embodiment shown in Figure g can be removed with an upwardly pull upon tabs 64 of bag 44.
In each of the above described embodiments of Figures 1-9, the engagement of bag lip 58 with housing 12 forms sub-stantially a hermetic seal between filter bag 44 and the housing at bag ring part 52. This causes the liquid level ~135~3~

ithin the fil~er to rcmain no h;~h~r than the bottom of lip 53 of ba~ ring part 52 upc~n r~mov~l o~ cap 22, allowing access to ta~s 64 when it is -lesirablc to r~move the fi].ter }-ac3~
By joinin~ wall part 50 to rin-3 part 52 of filter bag ~4 at lip 53 of the ring paxt, tlle diameter of the wall part can be precisely sized to accommodate the fi.lter llousing opening. This improve~ the filtering effic~ency of the filter.
~0 The fi.l~or embodiment illu~trated in ~igs. 10-12 includes a housiny 12 having a sidc wall 14 and a botto~
wall 16 c-lefinirlg an internal chamber 17. ~n opening 10 defined by side wall end ~dge 20 illtO chan~r 17 is formed i.n housing 12 and is opposLtely locatecl from bottom wall lG of the housing. A cap 22 spans c~peninc~ in housing 1~.
Cap 22 rcsts upon side wall ~nd e~lc~c 20 and i~ retaincd in posit:ion by a plurality of rernovable threacled hol(l-down mer~ers 24. An 0-ring 26 is placed in compression between cap 22 and }-ousing 12 so aY to provide a liquid seal between

2)0 tlle cap and housing.
Cap 22 includes an inl~t port 28 ~nd bottom wall 16 o housing 12 includes an outlet port 30 by which liquid can flow thr~uc3h fi.lter lO. Le~s 32 ar~ conn~cted to housing bottom wall 16 for tl~c pur~e o maintail-ing ~ilter lO in an upri~ht posit.ion dl~rinc~ u~e. I~ousing si-lc wall l~ carrie~ an annul;~r shouldcr 34 wllicll is spaccd from ~nd ecl(Je 20 of the hOUSillg. ~houlder 34 .include~ an end E~ce 80 which carrie~ diam~trically or~sed pins 82.
A tilt.er scrc~en 84 is fit~ed within hc)ll:;in(J 12. Scree~n

3~0 includ~s an annular sh~pe~ t~ining liquid i.mpervious 113923~

1 flan~e 86 and a wall. 'l`he wall of screen ~4 includes a ri~3id rin-3 part ~.~ joined to flan;3e 86 arld an enclosed reticulated filtering part 7Q wl)ich may be of a woven wixe, plastic or cloth material. Ring part 6~ has two diametrically located slots 72 formed in it. Each slot 72 includes a cam surface 74~ An O-ring 75 is carried upon shoulder 34.
l'o ass~ble screen 84, the screen is inserted into housing chamber 17 through opening 18. Th~- op~ning~ 78 lo into screen 510ts 72 are aligned with pins 82 ~nd screen 84 positioned with the pins located in the longitudinal portions of the slots. The screen is then turned relative to housing 12 to cause the pins to slidably engage c~m surfaces 74 of the slots which urges screen flanye 86 toward housiny shoulder 34. This compresses O-ring 76 between flange 86 and shoulder 34 -to form a circumferential liquid seal between housing 12 and screen 84. Screen 84 is removed from housing 12 by reverse turning of the screen~
In some embodiments screen 84 may be designed to carry the pins while housing shoulder and face 80 has the accommodating slots formed in it. Also the number of pins and accommodating locking slots can v~ry depending upon the ~ize of the filter. ~lso a filteriny bag could be used with screen 84.
In some em~odiments of t~is invention the filter could be designed so that both the inlet and outlet ports oE th~
~ilter are incorporated into the filter housing and not the filter cap. Further, it is to be ur-derstood that thi~
invention is not to be limited to the details above given and described, but may be modified within the scope of the ..ppended claims.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a liquid filter including a housing having a side wall defining a chamber therein, said chamber having an opening, an annular support carried by said housing and defining at least in part said chamber opening, an inlet port and an outlet port, the improvement comprising a filter bag having a wall part formed of a flexible liquid pervious mater-ial and a ring part formed of a shape-retaining liquid imper-vious material, said bag ring part including an annular lip defining the opening into said filter bag and an outturned annular flange, said bag wall part joined to said lip of the bag ring part, said filter bag fitting in said chamber with its wall part extending through said chamber opening within the path of liquid flow between said inlet and outlet ports and with its said ring part flange contacting said support, said ring part flange forming a circumferential hermetic seal between said ring part and housing.

2. The liquid filter of Claim 1 and reticulated basket including a marginal edge defining an opening into the basket, said basket fitted within said chamber and spaced from said housing side wall, said bag wall part extending into said basket and having said ring part flange of the bag overlying said basket marginal edge, said basket marginal edge constitut-ing a part of said support for said filter bag.

3. The liquid filter of Claim 1, wherein said ring part flange forms said circumferential hermetic seal between said ring part and said housing at all times when contacting said support.