DK155709B

DK155709B - FILTER UNIT FOR FITTING IN A VACUUM AIR EXHAUST OPEN

Info

Publication number: DK155709B
Application number: DK45575A
Authority: DK
Inventors: Hans Mathiesen Dall
Original assignee: Fisker & Nielsen As
Priority date: 1975-02-07
Filing date: 1975-02-07
Publication date: 1989-05-08
Also published as: NL181776B; NL7601133A; GB1527034A; NL181776C; DK155709C; DE2515910C2; SE410551B; DK45575A; CH597830A5; SE7601260L; DE2515910A1; SE7601260A

Description

1 · DK 155709B1 · DK 155709B

Opfindelsen angår et filteraggregat til montering i en støvsugers luftudblæsningsåbning og af den art, som har en udtagelig filterindsats med en ringformet, relativt stiv bæreplade, til hvis ene side et filtermateriale er lufttæt fastgjort, samt en aftagelig, gennembrudt hætte, der omgiver filterindsatsen.BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a filter assembly for mounting in an air exhaust vent of a vacuum cleaner and of the type having a removable filter insert with an annular, relatively rigid support plate to which one filter material is airtightly attached, and a removable, pierced cap surrounding the filter insert.

Et sådant filteraggregat indsættes i støvsugerens udblæsningsåbning, når støvsugeren anvendes på steder, hvor der stilles store krav til renheden af den udblæste luft, f.eks. i hospitaler, hvor det er betydningsfuldt, at bakterier i luften kan opsamles i filteret og risikoen for smittespredning'derved begrænses. Også i produktionslokaler, laboratorier og andre steder, hvor der stilles ekstremt høje krav til rumluftens støvfrihed, er et sådant filterag-Such a filter assembly is inserted into the exhaust vent of the vacuum cleaner when the vacuum cleaner is used in places where there are high demands on the purity of the exhausted air, e.g. in hospitals where it is important that bacteria in the air can be collected in the filter and the risk of infection spreading is thereby reduced. Also in production rooms, laboratories and other places where extremely high demands on room air dust are required,

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gregat af interesse, bl.a. fordi det gør det muligt at tilbageholde meget små støvpartikler, som stammer fra slid på støvsugerens bevægelige dele i motor- og blæseaggregatet, og som derfor ikke kan fraskilles i det normale, på blæserens indstrømsside placerede filter.gregat of interest, i.a. because it makes it possible to retain very small dust particles that result from wear of the moving parts of the vacuum cleaner in the engine and blower assembly, and which cannot therefore be separated in the normal filter located on the fan side of the fan.

Fra britisk patentskrift nr. 1 340 955 kendes et filteraggregat af den omhandlede art, hvor filterindsatsen er fastklemt aksialt mellem en endeflade på støvsugerens hus og en modstående flade på den gennembrudte hætte. Anlægstrykket mellem støvsugerhuset og filterindsatsen, som skal sikre den nødvendige tæthed ved indsatsens tilgangsende, skal således overføres gennem selve filtermaterialet eller, hvis dette ikke tåler den aksiale kraftpåvirkning, gennem særskilte kraftoverførende elementer, f.eks, et stift hus fastgjort mellem indsatsens to ender. Da filterindsatsen bortkastes efter brugen, er det ønskeligt at holde dens pris lav og dermed også at undgå sådanne fordyrende ekstraelementer.British Patent Specification No. 1,340,955 discloses a filter assembly of the kind in which the filter insert is axially clamped between an end surface of the vacuum cleaner housing and an opposite surface of the pierced cap. The system pressure between the vacuum cleaner housing and the filter insert, which is to ensure the necessary tightness at the inlet end of the insert, must thus be transmitted through the filter material itself or, if this does not withstand the axial force effect, through separate power transfer elements, for example a rigid housing fixed between the two ends of the insert. As the filter insert is discarded after use, it is desirable to keep its price low and thus also to avoid such expensive extras.

Dette opnås ved filteraggregatet ifølge opfindelsen, som er ejendommeligt ved, at det har en basisdel med koblings- og tætningsorganer til lufttæt sammenkobling med modsvarende organer på støvsugerens hus, en fra koblings- og tætningsorganerne bortvendende studs og en omkring studsen anbragt, af elastisk materiale bestående ring, som i ubelastet tilstand har let pasning i bærepladens åbning, samt en spændemekanisme omfattende en på den ene side af ringen til studsen fastgjort trykskive og en på ringens modsatte side langs studsen forskydelig trykskive, der er fjederbelastet i retning mod den faste trykskive.This is achieved by the filter assembly according to the invention, which is characterized in that it has a base part with coupling and sealing means for airtight coupling with corresponding means on the vacuum cleaner housing, a studs facing away from the coupling and sealing means and an elastic material arranged around the plug. ring, which in unloaded condition has easy fit in the opening of the support plate, as well as a clamping mechanism comprising a pressure disc fixed on one side of the ring to the spigot and a pressure disc which is displaceable on the opposite side of the spigot, which is spring-loaded towards the fixed pressure disc.

I aggregatet ifølge opfindelsen fastholdes filterindsatsen ved indgrebet mellem indsatsens ringformede bæreplade og den radialt ekspanderede elastiske ring, som samtidig skaber tætning mellem støvsugerhuset og indsatsen, og selve filtematerialet er derfor helt upåvirket af mekaniske kræfter. Da indsatsen alene består af filtermaterialet og den ringformede bæreplade samt eventuelt - afhængigt af filtematerialets udformning - en modstående, helt lukket endeplade, er dens fremstillingspris så lav som praktisk opnåeligt. Fjederbelastningen på den aksialt forskydelige trykskive frembringer den nødvendige radiale ekspansion af den elastiske ring ved aksial sammentrykning af ringen, og monteringen af filterindsatsen er dermed væsentlig enklere, end hvis ringen skulle klemmes sammen ved hjælp af skruer eller tilsvarende manuelt betjente spændeorganer.In the assembly according to the invention, the filter insert is retained by the engagement of the annular support plate of the insert with the radially expanded elastic ring, which simultaneously creates a seal between the vacuum cleaner housing and the insert, and the felt material itself is therefore completely unaffected by mechanical forces. Since the insert consists solely of the filter material and the annular support plate and possibly - depending on the design of the felt material - an opposing, fully closed end plate, its manufacturing cost is as low as practicable. The spring load on the axially displaceable pressure washer provides the necessary radial expansion of the elastic ring by axial compression of the ring, thus mounting the filter insert is substantially simpler than if the ring were to be clamped by screws or similar manually operated clamping means.

Der opnås også en yderst ensartet fordeling af anlægskraften langs ίThere is also a very uniform distribution of construction power along ί

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omkredsen af den elastiske ring, fordi den aksiale fjederbelastning på ringen virker ensartet langs hele ringens anlægsflade mod trykskiven. Da fjederkraften er givet på forhånd, kan også den radialt virkende anlægskraft mellem ringen og bærepladen fastlægges på en værdi, som på den ene side er tilstrækkelig til at forebygge utæthed og på den anden side ikke medfører risiko for overbelastning af komponenterne. Bærepladen kan derfor også gøres forholdsvis tynd, hvilket giver en materialebesparende og dermed billig filterindsats. Montøingen og demonteringen af filterindsatsen kan foregå uden anvendelse af værktøj og speciel fagkundskab, hvilket især i hospitaler er af praktisk værdi.the circumference of the elastic ring because the axial spring load on the ring acts uniformly along the entire contact surface of the ring against the pressure washer. Since the spring force is given in advance, the radially acting contact force between the ring and the support plate can also be determined at a value sufficient on the one hand to prevent leakage and on the other hand does not entail the risk of overloading the components. The support plate can therefore also be made relatively thin, which gives a material saving and thus cheap filter insert. The mounting and disassembly of the filter insert can be done without the use of tools and specialized expertise, which is especially useful in hospitals.

Den elastiske ring kan i ubelastet tilstand have tæt pasning omkring studsen, hvilket giver en optimal udnyttelse af deformationsarbejdet ved ringens aksiale sammentrykning, idet ringens radiale ekspansion for den overvejende dels vedkommende foregår i retning udefter.The elastic ring may have a tight fit around the bounce in an unstressed state, which provides optimal utilization of the deformation work by the axial compression of the ring, the radial expansion of the ring for the most part being in the outward direction.

Ringen har fortrinsvis ϋ-formet aksialt tværprofil med den konvekse side vendende udad og med større godstykkelse i profilets to ben end i den mellemliggende kropdel af profilet. Ved denne udformning sikres med lille materialeforbrug en maksimal deformation i ringens kropdel, idet de stivere ben virker som vægtstænger, der. omsætter den aksiale kraftpåvirkning til radial ekspansion af ringen. På grund af kropdelens lave stivhed kan den endvidere let tilpasse sig eventuelle unøjagtigheder i formen og dimensionerne af bærepladens åbning og derved sikre effektiv tæthed.The ring preferably has a ϋ-shaped axial transverse profile with the convex side facing outwards and with greater thickness in the two legs of the profile than in the intermediate body part of the profile. In this design, with little material consumption, a maximum deformation in the body part of the ring is ensured, with the stiffer legs acting as barbs which. translates the axial force influence to radial expansion of the ring. Furthermore, due to the low rigidity of the body part, it can easily adapt to any inaccuracies in the shape and dimensions of the aperture of the support plate, thereby ensuring effective tightness.

I forbindelse hermed er det hensigtsmæssigt, at den aksiale udstrækning af U-profilets kropdel er væsentlig større end tykkelsen af bærepladen. Ringens kropdel vil da i sin deformerede tilstand bule ind over bærepladen på begge sider af denne og derved fremkalde en vis positiv låsevirkning foruden det af ringens ekspansion betingede friktionsanlæg mod kanten af åbningen. Den forøgede bredde af ringen kompenserer også for en eventuel mindre nøjagtig aksial placering af bærepladen i forhold til ringen.In this connection, it is preferred that the axial extent of the body portion of the U-profile is substantially greater than the thickness of the support plate. The body portion of the ring will then, in its deformed state, bulge over the support plate on both sides thereof, thereby causing some positive locking action in addition to the friction abutment condition conditioned by the ring against the edge of the opening. The increased width of the ring also compensates for any less accurate axial placement of the support plate relative to the ring.

Fortrinsvis er den forskydelige trykskive drejelig omkring studsen og har mindst én aksialt orienteret knastflade, som samvirker med en modstående knastflade på aggregatets basisdel, og fjederbelastningen påvirker skiven til drejning. Ved passende udformning af de samvirkende knastflader opnår man en yderligere kraftforstærkning, som gør det muligt at tilvejebringe en høj aksialkraft med enPreferably, the displaceable pressure disc is rotatable about the bounce and has at least one axially oriented cam surface which cooperates with an opposing cam surface on the base of the assembly, and the spring load affects the disk for rotation. By appropriately designing the cooperating cam faces, an additional force gain is obtained which allows a high axial force with a

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forholdsvis lille fjederkraft. Derved lettes filterindsatsens montering og demontering, hvor fjederkraften skal overvindes, således at operatøren hertil kun behøver to fingre, medens den anden hånd er fri til styring af filterindsatsen.relatively small spring force. This facilitates the mounting and disassembly of the filter insert where the spring force must be overcome, so that the operator needs only two fingers for this purpose, while the other hand is free to control the filter insert.

Det er hensigtsmæssigt at udforme spændemekanismen således, at den elastiske ring i sin virksomme tilstand holder bærepladen fri af berøring med uelastiske dele i aggregatet. Da filterindsatsen på denne måde kommer til at "svæve" frit i den omgivende hætte, undgår man risikoen for, at det ofte ret fugtfølsomme materiale udsættes for mekanisk overbelastning i tilfælde af en ekspansion under filteraggregatets drift.It is convenient to design the clamping mechanism so that the elastic ring in its operative state keeps the support plate free from contact with inelastic parts in the assembly. In this way, as the filter insert will "float" freely in the surrounding cap, the risk of the often quite moisture-sensitive material being exposed to mechanical overload in the event of an expansion during the operation of the filter assembly is avoided.

Opfindelsen forklares i det følgende nærmere med henvisning til den skematiske tegning, på hvilken fig. 1 viser et sidebillede, delvis i aksialt snit af en udførelsesform for et filteraggregat ifølge opfindelsen monteret på en støvsuger, fig. 2 et planbillede af den ene del af filteraggregatets hus set i retning af pilen II i fig. 1, fig. 3 et tilsvarende billede med visse detaljer udeladt for overskuelighedens skyld og visende dele af spændemekanismen i to forskellige stillinger, og fig. 4 et snit efter linien IV-IV i fig. 3.The invention will now be explained in more detail with reference to the schematic drawing, in which FIG. 1 is a side view, partly in axial section, of an embodiment of a filter assembly according to the invention mounted on a vacuum cleaner; FIG. 2 is a plan view of one part of the filter assembly housing as seen in the direction of arrow II in FIG. 1, FIG. 3 shows a similar view with certain details omitted for the sake of clarity and showing parts of the clamping mechanism in two different positions; 4 is a section along line IV-IV of FIG. Third

Den støvsuger, hvorpå det på tegningen viste filteraggregat er aftageligt monteret, er i fig. 1 anskueliggjort ved hjælp af støvsugerhusets topstykke 1, som ved hjælp af ikke viste spændeorga-ner er fastgjort til den øverste del af støvsugerens ikke viste hus, hvorved en tætningsring 2 klemmes fast mellem topstykket og huset. Skruer 3 tjener til at fastgøre dels tætningsringen, dels et hus 4 for støvsugerens ikke viste motor og blæseraggregat til topstykket 1. I fig. 1 ses motorens aksel 5, som bærer en totrins centrifugalblæser 6, der samvirker med to sæt stationære ledeskovle 7 og 8 for den af blæseren transporterede og i støvsugerens hus filtrerede luft. Som vist med pile i fig. 1 passerer luften fra det sidste sæt ledeskovle 8 gennem en ringformet passage 9, der afgrænses mellem en tværvæg 10 og en ringformet skillevæg 11, og ud gennem en cirkulær åbning 12 beliggende centralt i væggen 11. Åbningen 12 er med radial afstand omgivet af en ringformet krave 13, som rager op fra væggen 11.The vacuum cleaner on which the filter assembly shown in the drawing is removably mounted is shown in FIG. 1 is illustrated by means of the head piece 1 of the vacuum cleaner housing, which is secured by means of clamping means not shown to the upper part of the housing of the vacuum cleaner not shown, whereby a sealing ring 2 is clamped between the head piece and the housing. Screws 3 serve to secure partly the sealing ring and partly a housing 4 for the vacuum cleaner motor and fan assembly to the head piece 1. In FIG. 1, the shaft 5 of the engine is shown, which carries a two-stage centrifugal fan 6, which cooperates with two sets of stationary guide vanes 7 and 8 for the air transported and filtered in the fan by the fan. As shown by arrows in FIG. 1, the air from the last set of guide vanes 8 passes through an annular passage 9 bounded between a transverse wall 10 and an annular partition 11 and out through a circular opening 12 located centrally in the wall 11. The opening 12 is radially spaced by an annular collar 13, projecting from wall 11.

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Topstykket 1 har en relativt stor central åbning 14, langs hvilken der er udformet et antal indadvendende fremspring 15, som sammen med modsvarende tunger 16 på det i det følgende nærmere beskrevne filteraggregat danner en bajonetlås, hvormed filteraggregatet kan fastgøres aftagelig til topstykket 1. Filteraggregatet omfatter et hus bestående af to aftageligt sammenkoblelige dele, nemlig en nedre skiveformet del 17 og et klokkeformet dæksel 18. Delen 17 er støbt af plast ud i ét med en central studs eller bøsning 19, til hvis nedadvendende endeflade en af elastisk materiale bestående tætningsmanchet 20 er fastholdt ved hjælp af en låsering 21. De ovenfor omtalte tunger 16 i bajonetlåsen er Udformet på en ring, som er belastet opefter i retning mod topstykket 1 ved hjælp af fjedre 22 mellem ringen og låseringen 21. Når filteraggregatet er monteret som vist i fig. 1, ligger manchetten 20 tætnende an mod overkanten af kraven 13 under indflydelse af manchettens fjederkraft, som skyldes dens aksiale sammentrykning.The head piece 1 has a relatively large central aperture 14 along which a number of inwardly projecting projections 15 are formed which together with corresponding tongues 16 on the filter assembly described below, a bayonet lock with which the filter assembly can be removably attached to the head piece 1. The filter assembly comprises a housing consisting of two removably interconnectable portions, namely a lower disc-shaped portion 17 and a bell-shaped cover 18. The portion 17 is molded of plastic integrally with a central stud or sleeve 19, the downward-facing end face of which is a sealing sleeve 20 of elastic material. held by means of a locking ring 21. The above-mentioned tongues 16 in the bayonet lock are formed on a ring which is loaded upwards towards the head piece 1 by means of springs 22 between the ring and the locking ring 21. When the filter assembly is mounted as shown in FIG. 1, the sleeve 20 abuts against the upper edge of the collar 13 under the influence of the spring force of the sleeve due to its axial compression.

Til den øverste ende af studsen 19 er en trykskive 23 fastgjort ved hjælp af en krave, som rager ind i studsen 19 og er bertlet om mod en vulst langs dennes kant. En anden trykskive 24 er aksialt forskydelig med let pasning langs studsen 19's yderside og samtidig drejelig om studsens længdeakse. Mellem de to trykskiver 23 og 24 ligger en kombineret koblings- og tætningsring 25, som er fremstillet af elastomert materiale, og som i aksialt tværsnit har form som et indefter åbent U med to skrå ben 26 og 27 samt en mellemliggende kropdel 28. I den viste udførelsesform har benene 26 og 27 voksende godstykkelse indefter mod ringens akse, og kropdelen 28 er væsentlig tyndere end de to ben.At the upper end of the connector 19, a pressure washer 23 is secured by a collar which projects into the connector 19 and is braced against a bead along its edge. Another thrust washer 24 is axially displaceable with easy fit along the outer side of the connector 19 and at the same time rotatable about the longitudinal axis of the stud. Between the two pressure washers 23 and 24 lies a combined coupling and sealing ring 25, which is made of elastomeric material and which in axial cross section has the shape of an inner open U with two inclined legs 26 and 27 and an intermediate body part 28. In the In the embodiment shown, the legs 26 and 27 have increasing thickness inwards towards the axis of the ring, and the body part 28 is substantially thinner than the two legs.

I ringen 25's ubelastede tilstand ligger det øverste ben 26 med let pasning an mod ydersiden af studsen 19, medens det nederste ben 27 styres af en krave på en ring 29, som ligger oven på trykskiven 24 og sammen med denne er forskydelig langs studsen 19.In the unloaded state of the ring 25, the upper leg 26 readily adheres to the outside of the plug 19, while the lower leg 27 is guided by a collar on a ring 29 which is on top of the pressure disc 24 and together with it is displaceable along the plug 19.

Den bevægelige trykskive 24 er udformet med to radialt udragende betjeningsarme 30, som ved hjælp af to trækfjedre 31 er forbundet med den skiveformede del 17 af filteraggregatets hus. Fire akseparallelle tappe 32 rager opefter fra delen 17, og som vist i fig. 2 og 3 tjener to af tappene som anslag til begrænsning af trykskiven 24's drejning under påvirkning af fjedrene 31.The movable pressure washer 24 is formed with two radially projecting operating arms 30, which are connected by means of two tension springs 31 to the disc-shaped part 17 of the housing of the filter assembly. Four axis parallel pins 32 extend upwardly from the portion 17, and as shown in FIG. 2 and 3, two of the pins serve as stops for limiting the rotation of the pressure disc 24 under the influence of the springs 31.

Husdelen 17 bærer endvidere seks jævnt om studsen 19's akse fordelte opadragende knaster 33 med opadvendende skråThe housing part 17 also carries six evenly spaced upwardly extending cams 33 with upwardly inclined socket 19 on the axis 19

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knastflader 34, og seks modsvarende knaster 35 med nedadvendende skrå knastflader 36 rager ned fra trykskiven 24. Knastfladerne, der kan være formet som dele af skrueflader, har en sådan hældning, at trykskiven 24 løftes, når den under indflydelse af fjedrene 31 drejer mod urviserretningen som set i fig. 2 og 3.cam faces 34, and six corresponding bosses 35 with downwardly inclined cam faces 36 project downwardly from the pressure washer 24. The cam faces, which may be formed as portions of screw faces, are inclined such that the pressure washer 24 is lifted when under the influence of the springs 31 in a clockwise direction. as seen in FIG. 2 and 3.

En i og for sig kendt filterindsats eller -patron 37 består af to parallelle endeplader 38 og 39 af relativt tyndt, men stift materiale, eksempelvis phenolplast, samt en filterdug 40, der er harmonikafoldet og derefter dannet til en hulcylinder, hvis ender er hermetisk fastgjort til endepladerne 38 og 39, f.eks. ved hjælp af en hærdelig klæbe- eller støbemasse. Pladen 38 er ugen-nembrudt, medens pladen 39 har en central åbning, hvis diameter er en lille smule større end yderdiameteren af koblings- og tætningsringen 25 i dennes ubelastede tilstand.A known filter insert or cartridge 37 known per se consists of two parallel end plates 38 and 39 of relatively thin but rigid material, for example phenolic plastic, and a filter cloth 40 which is folded in harmony and then formed into a hollow cylinder whose ends are hermetically fastened. to the end plates 38 and 39, e.g. using a curable adhesive or molding compound. The plate 38 is perforated weekly, while the plate 39 has a central opening whose diameter is slightly larger than the outer diameter of the coupling and sealing ring 25 in its unstressed state.

To diametralt modstående flige 41 rager op fra husdelen 17 og er udformet med indstøbte gevindbøsninger 42 til optagelse af skruer 43, hvormed dækslet 18 fastgøres aftageligt til delen 17. Skruerne 43 tjener samtidig til fastgørelse af en bøjle 44, hvormed støvsugeren kan løftes og transporteres, når filteraggregatet ved hjælp af den før omtalte bajonetkobling 15, 16 er fastgjort i topstykket 1. Som vist i fig. 1 er dækslet 18 udformet med slidser 45 og 46, gennem hvilke udblæsningsluften fra støvsugeren afgives til omgivelserne efter at være passeret gennem filterdugen 40, således som det er antydet med pile i fig. 1 og 4.Two diametrically opposed tabs 41 protrude from the housing portion 17 and are formed with embedded threaded bushes 42 for receiving screws 43, thereby securing the cover 18 to the portion 17. The screws 43 simultaneously serve to secure a hanger 44 by means of which the vacuum cleaner can be lifted and transported. when the filter assembly is secured to the head piece 1 by means of the aforementioned bayonet coupling 15, 16 as shown in FIG. 1, the cover 18 is formed with slots 45 and 46 through which the exhaust air from the vacuum cleaner is discharged to the environment after passing through the filter cloth 40, as indicated by arrows in FIG. 1 and 4.

Når en filterindsats 37 skal monteres, tager man først dækslet 18 af, hvorefter man mod fjedrene 31 drejer den bevægelige trykskive 24 i urviserretningen (som vist i fig. 2 og 3) til den stilling, der ses til venstre i fig. 3 og 4. Drejningen kan foretages med to fingre, der trykker mod henholdsvis én af armene 30 og den ene flig 41, som for overskuelighedens skyld er udeladt i fig. 3. Som følge af de ovenfor omtalte skrå knastflader 34 og 36 medfører drejningen, at trykskiven 24 samtidig bevæger sig nedad under indflydelse af ringen 25's elasticitet, og i denne stilling af de omtalte dele kan filterindsatsen 37 nu sættes ned over ringen 25 på grund af spillerummet mellem dennes krppdel 28 og åbningen i filterindsatsens bundplade 39. Ved påsætningen kan pladen 39 støtte mod oversiden af knasterne 32, som det også ses i fig. 4's venstre halvdel.When a filter insert 37 is to be mounted, the cover 18 is first removed, after which the movable pressure washer 24 is turned clockwise (as shown in Figures 2 and 3) to the position seen to the left in Figs. 3 and 4. The rotation can be made with two fingers pressing against one of the arms 30 and one tab 41 respectively, which for the sake of clarity are omitted in FIG. 3. As a result of the above mentioned inclined cam faces 34 and 36, the rotation causes the pressure disc 24 to simultaneously move downward under the influence of the elasticity of the ring 25, and in this position of the mentioned parts, the filter insert 37 can now be lowered over the ring 25 due to the clearance between its crepe portion 28 and the aperture in the bottom plate 39 of the filter insert. Upon application, the plate 39 can support the upper side of the lugs 32, as also seen in FIG. 4's left half.

Claims

A filter assembly for mounting in a vacuum extractor opening of a vacuum cleaner and of the type having a removable filter insert (37) with an annular, relatively rigid support plate (39), to which one side a filter material (40) is airtightly attached, and a removable, pierced cap (18) surrounding the filter cartridge, characterized in that the unit also has a base part (17) with coupling and sealing means (16, 20) for airtight coupling with corresponding means (15, 13) on the vacuum cleaner housing, one from coupling - and sealing

Filter assembly according to claim 1, characterized in that the elastic ring (25) has a tight fit around the plug (19) in the unstressed state.

Filter assembly according to claim 1 or 2, characterized in that the ring (25) has a U-shaped axial cross profile with the convex side facing outwards.

Filter assembly according to claim 3, characterized in that the thickness of the goods in the two legs (26, 27) of the ring profile is greater than in the intermediate body part (28) of the profile.

Filter assembly according to claim 3 or 4, characterized in that the legs (26, 27) of the ring profile have a decreasing thickness of the goods.

Filter assembly according to any one of claims 3-5, characterized in that the axial extension of the body part (28) of the U-profile is substantially greater than the thickness of the filter plate carrier (39).

Filter assembly according to any one of claims 1-6, characterized in that the displaceable pressure disc (24) is rotatable about the plug and has at least one axially oriented cam surface (36) which cooperates with an opposing cam surface (34) on the base part (17). ), and that the spring load affects the dial for rotation.

7 DK 155709 B When the arm 30 is then released, the movable pressure disk 24 rotates counterclockwise under the action of the springs 31, and due to the inclined cam faces 34 and 36 this rotation is accompanied by a lifting of the disk 24 which compressively the ring 25 between the two disks 23 and 24, as seen on the right in FIG. 3 and 4. The ring 25 hereby expands radially so that its body part 28 will abut close to the opening in the bottom plate 39 of the filter insert, while at least the upper leg 26 of the ring comes in corresponding sealing and power-transferring systems against the plug 19 By appropriately selecting the dimensions of the ring 25, forces can be provided between this and the plate 39, respectively, the socket 19, which fully guarantees the retention and sealing of the filter insert. When the body portion 28 of the ring 25 has a suitably small thickness, after expansion, it will bulge a distance beyond the edge of the opening in the plate 39 on both sides thereof, further improving both the tightness and the retention. The prior axial location of the filter insert by the stop pins 32 ensures that the abutment between the body portion 28 of the ring and the plate 39 occurs in the desired area of the body portion width, usually in the middle or a negligibility below the center width. After applying the filter insert, the cover 18 and the bracket 44 are reattached by means of the screws 43. Replacement of a filter which has reached a predetermined degree of clogging takes place in the same manner as described above, and after removing the cover 18 and the bracket 44, it rotates. movable pressure washer 24 by means of the operating arm 30, which allows the ring 25 to expand axially, thereby simultaneously contracting radially so that the filter insert 37 is no longer retained and can therefore be removed.

Filter assembly according to any one of claims 1-7, characterized in that the base part (17) of the assembly has an outwardly extending stop member (32) for cooperating with the filter plate's supporting plate (39) when inserting the insert.

8 means 155 (9) facing away from the members and an elastic material ring (25) arranged around the plug, which in an unstressed state easily fits in the opening of the support plate (39), and a clamping mechanism comprising. a pressure disc (23) fixed on one side of the ring (25) to the plug, and a pressure disc (24) displaceable along the plug along the stud spring-loaded in the direction of the first pressure disc (23).

Filter assembly according to claims 7 and 8, characterized in that the stop means (32) is simultaneously designed as a stop for the rotatable and axially displaceable pressure disc (24).

Filter assembly according to any of claims 1-9, characterized in that the clamping mechanism is designed such that the elastic ring (25) in its operative state keeps the support plate (39) free from contact with inelastic parts in the assembly.