A FLUID FILTER, MORE PARTICULARLY SPIN-ON TYPE FLUID FILTER

Abstract: A filter, in particular a fluid filter of the "spin-on" type, comprising a head with an inlet space and an outlet space and with a coaxially extending connecting spigot, a housing with one open end, said housing containing an annular-cylindrical filter element and having a terminal edge, that confines said open end and sealingly engages a groove provided in the body of said head and positioned coaxially around said connecting spigot, as well as an annular disc-shaped intermediate piece screwed onto said connecting spigot and supporting said filter element. An edge portion of said intermediate piece extending beyond said filter element is screwed into said housing and is provided with passage openings. Head, intermediate piece and filter housing are sealingly assembled with one single sealing ring.

Description: Short title: A fluid filter, more particularly spin-on type fluid filter. The invention relates to a filter as defined in the first part of claim 1. Such a filter, which in professional circles is called "spin-on filter", is disclosed in EP-A-0 616 825 (see the embodiment according to Fig. 3 and 5) . With this well-known filter the cup-shaped filter housing is externally threaded and screwed into a corres¬ pondingly internally threaded skirt portion of the inter¬ mediate piece, the terminal edge of the housing bearing against a sealing ring provided in a groove in the inter¬ mediate piece. The intermediate piece has a second sealing ring on the side turned towards the head, which sealingly engages a lower annular surface of the head. The filter according to the present invention distin- guishes from this well-known filter by the features which are mentioned in the second part of claim 1. The filter according to the invention has the advan¬ tage, that the head, the intermediate piece and the filter housing can be sealingly assembled by means of one single sealing ring. Moreover the intermediate piece may be kept substantially lighter. It is to be remarked, that US-A-5 342 519 discloses a filter of the "spin-on" type, with which the housing is also internally threaded and screwed onto a correspon- dingly externally threaded circumferential portion of an intermediate piece. In this case, however, like the filter according to EP-A-0 616 825, two separate sealing rings are required for assembling the filter, the intermediate piece and a head (not shown in US-A-5 342 519) . A preferred embodiment of the filter according to the invention has the features mentioned in claims 2 and 3 as well. By forming the passage openings as circumferential recesses the annular face of the intermediate piece sup- porting the filter element is correspondingly increased, which makes the filter suitable for higher pressures. The filter according to the invention is particularly suitable for use with a filter element of the type disclo- sed in NL-A-1001867. Correspondingly a practical embodiment of the filter according to the invention has also the features of claims 5 and 6. The invention will be hereinafter further explained by way of example with reference to the drawing. Fig. 1 is a vertical cross-sectional view of the filter according to the invention and Fig. 2 is a plan view of a support plate with which the circumferential recesses are, as distinguished from what is shown in Fig. 1, positioned pairwise diametrically opposite to one another. The liquid filter shown in the drawing, which is more particularly adapted as an oil filter, comprises a head A and a housing B. The head A mainly consists of a cap- shaped body with an upper wall 1 and a circumferential wall 2, the enlarged lower edge 3 of which has an annular groove 4 for receiving sealing material 5. At two diame¬ trically opposite locations the circumferential wall 2 is provided with an inlet connection 6 and an outlet connec- tion 7 respectively. The outlet connection 7 is connected to an outlet space 8, which is confined by a connecting spigot 9, that extends from the upper wall 1 downwardly. The inlet connection 6 is connected to the remainder of the cap space, which constitutes the inlet space 10. An annular disc-shaped support plate 11 is screwed on the externally threaded lower end of the connecting spigot 9. This support plate has a central, downwardly extending collar 12 and is correspondingly internally threaded. The support plate 11 has an enlarged circumferential edge 13, which is externally threaded. For the rest the support plate 11 is completely flat. The housing B is a metallic housing 14, which is closed at one end by a convex end wall 15 and has its open upper end screwed on the enlarged circumferential edge 13 of the support plate 11. The housing may be manufactured in a well-known manner, e.g. by cold extrusion. In operational condition the housing 14 screwed onto the support disc 11 extends with its upper terminal edge 16 beyond the enlarged circumferential edge 13 of the support disc into the groove 4 of the head and thereby in sealing contact with the sealing material 5. Within the housing 14 there is an annular cylindrical filter element 17. This filter element comprises in a well-known manner an annular cylindrical filter body 18 formed of pleated filtering cloth and provided on the inner side with a metallic, perforated tube 19. The filter body bears with its lower annular end wall on a metallic bottom plate 20 which in turn is resiliently supported by the convex end wall 15. The filter element 17 is preferably formed in the manner disclosed in NL-A-1001867, i.e. with the terminal ends of the cylindrical filter body (formed of pleated filtering cloth) embedded in sealing rings 21 and 22 respectively of a flexible type of rubber or similar elastomeric material. This enables the annular cylindrical filter body to bear with the upper sealing ring 22 direct- ly against the flat lower face of the support plate 11. The internal metallic support tube 19 may be fastened to the bottom plate 20 and is centered at its upper end by the collar 12 of the support plate 11. As is particularly shown in Fig. 2, the support plate is provided with circumferential recesses 23 at circumfe- rentially spaced locations, which recesses constitute connecting or passage openings between the inlet space 10 and the space 24 around the filter element 17. The flow path of the liquid to be filtered and of the filtered liquid is indicated by arrows. When the filter has become filthy the filter housing 14 is simply unscrewed, while the support plate 11 is left in place. This releases the filter element 17 from the support plate 11 so that the part 18 of it may be simply replaced by a fresh one, after which the assembly may be put back into the operational condition by re-fastening (screwing) the filter housing.

Claims: C L A I M S 1. A filter, in particular a fluid filter, comprising a head (A) with an inlet space (6, 10) , an outlet space (7, 8) and a coaxially extending connecting spigot (9), an annular disc-shaped intermediate piece (11) scre¬ wed onto said connecting spigot (9) and sealed to prevent leakage toward the outside and a cup-shaped filter housing (B, 14) , containing an annular-cylindrical filter element and having its terminal edge sealingly screwed onto a circumferential portion of the annular disc-shaped intermediate piece, the filter element (17, 18, 19) having its annular end face turned away from the closed filter housing end (15) bearing against the intermediate piece (11) , the circumferential portion of the intermediate piece being provided with passage openings (23) , which connect the space (24) between the filter element (17, 18, 19) and the filter housing (B, 14) to the inlet/outlet space (10) in the head (8) , characterized in that the filter housing (B, 14) is inwardly threaded and screwed on the corresponding threa¬ ded outer circumferential wall of the intermediate piece (11) , the terminal edge (16) of said filter housing bea- ring against a sealing ring (5) , which is received in a groove (4) in an annular face (3) of the head (A) that surrounds said connecting spigot (9) . 2. A filter according to claim 1, characterized in that the intermediate piece (11) has a circumferential edge portion (13) which is enlarged towards the head (A) . 3. A filter according to claims 1-2, characterized in that the passage openings (23) are formed as circumferen¬ tial recesses of the intermediate piece (11) . 4. A filter according to claims 2 and 3, characterized in that the intermediate piece (11) with its enlarged circumferential edge (13) is bearing against an inner circumferential wall portion confining said groove (4) for said sealing ring (5) inwardly. 5. A filter according to claims 1-4, characterized in that the annular cylindrical filter element is directly and sealingly bearing with its upper edge, formed by an annular disc of a flexible type of rubber or similar elastomeric material, against the substantially flat lower face of the intermediate piece. 6. A filter according to claims 1-5, characterized in that the intermediate piece (11) is provided at its inner circumference with a downwardly extending collar (12) , which projects into the upper end of a perforated tube (19) that supports the proper filter element formed of pleated filtering cloth.

Inventors: BARTELS ANTONIUS JOSEPHUS, VLEEMINGH GEURT JAN HENDRIK, BARTELS, ANTONIUS, JOSEPHUS, VLEEMINGH, GEURT, JAN, HENDRIK
Applicants: BARTELS ANTONIUS JOSEPHUS, FAIREY ARLON BV, VLEEMINGH GEURT JAN HENDRIK, BARTELS, ANTONIUS, JOSEPHUS, FAIREY ARLON B.V., VLEEMINGH, GEURT, JAN, HENDRIK
Application year: 1997
Main classification: B01D29
IPC codes: B01D29, B01D35