Title of Invention

"RILOZOLE AND ALPHA-TOCOPHEROL COMBINATION"

Abstract

The present invention discloses a filter element provided with a central opening (16) and designed to be assembled with an element of the same type to form a filter, each filter element (1) having two faces, one inside the filter and the other outside the filter (2, 3), an inner rim (5) defining the outline of the central opening (16) and a peripheral outer rim (4) with a screen (6) mounted between the rims parallel to said inside and outside faces (2, 3), each face of the element also having radial ribs (72, 73) extending in register between the outer and inner rims (4, 5) to form angular sectors (21, 31) on the inside face (2) and on the outside face (3) , each rib (72) of the inside face (2) of one of the elements coming into contact with a facing rib (72) of the inside face (2) of the other element to define cells (17) fed firstly via admission passages (9) formed through the inner rim (5) of each sector (31) of the outside face (3) of each element and opening out to the outside, and secondly via delivery passages (10) formed through the outer rim (4) of each sector (21) of the inside face (2) of each element, each delivery passage (10) of one of the elements being placed in register with a passage (10) of the other element and together forming a delivery orifice (18), the filter element being characterized in that each inside face (2) and each outside face (3) comprises at least sixteen angular sectors (21, 31), each sector being formed by a free portion of screen (6), and in that the ratio of the free filter area of the screen (6) over the total area of the element (1) lies in the range 55% to 68%. Representative Figure : Fig. 1.

Full Text

FILTERING ELEMENT FOR USE IN A FILTERING DEVICE The present invention relates to a filter element for use in a filter device. More particularly, the invention relates to a filter element provided with a central opening and designed to be assembled with an element of the same type so as to form a filter. The filter is suitable for being associated with other filters, thereby constituting a filter block for placing inside a case to make a filter cartridge. In general, each filter element has two faces, one inside and the other outside the filter, and an inner rim defining the outline of the central opening and a peripheral outer rim with a screen mounted between the rims parallel to said inside and outside faces. Each face of the filter element also has radial ribs extending in register between the inner and outer rims to form angular sectors on the inside and outside faces. Furthermore, each rib on the inside face of one of the elements comes into contact with a facing rib on the inside face of the other element so as to define cells which are fed firstly via admission passages formed through the inner rim in each sector of the outside face of each element and opening out to the outside, and secondly via delivery passages formed through the outer rim of each sector of the inside face of each element, each delivery passage of one of the elements being placed in register with a passage of the other element so as to form a delivery orifice. These filter elements generally have a central opening to form a feed duct which is thus disposed on the axis of the filter, the fluid for filtering penetrating into the filter via the admission passages formed through the inner rim and leaving it via the delivery passages formed through the outer rim, or vice versa. The filter cartridges generally in use comprise at least one filter plus a distributor for distributing the fluid to be filtered, the distributor being mounted rotatably on the axis inside the duct. The distributor is provided with a sectioning chamber for periodically isolating at least two angular sectors disposed on the outside face of each filter element, and communicating at this particular moment solely with the two sectors by means of passages made through the inner rims of said sectors. In a variant embodiment, the filter device further comprises a sealing and guiding sheath mounted coaxially between the distributor and the filter. The sheath has a plurality of orifices in its cylindrical wall so that said orifices are situated facing admission passages of at least one filter forming the filter block. Thus, a portion of the fluid that has already been filtered is introduced as a back flow via the delivery orifices and then into the angular sectors that have been isolated so as to enable their portions of the screen to be cleaned by back-washing. As a result, it must be observed that an isolated sector is a sector which does not contribute to active filtering of the fluid to he purified. Since known filter elements generally possess eight angular sectors per inside and outside face, it follows that during successive closure at determined moments of two sectors at a time, the filter capacity of the filter is about 75%. Furthermore, each angular sector of the filter elements includes a radial frame extending between the inner and outer rims, and concentric annular reinforcement extending transversely as two consecutive radial ribs. Thus, the filter capacity of the filter is further decreased because of the screen being masked by said reinforcement, which is contrary to the desired objective. Furthermore, known filter elements are made of metal and more generally of aluminum, thus giving rise to the presence of swarf between the screen and the radial ribs, the inner and outer rims, and also the radial and annular reinforcement. A major drawback of having such swarf present is that the mesh in a portion of the screen can become blocked, thereby likewise reducing filter capacity. Furthermore, said swarf is liable to become detached and thus to be conveyed in the supposedly purified fluid, and that can have particularly harmful effects on the mechanical members situated downstream from the filters. Furthermore, the screens used with known filter elements are themselves made of metal and usually of stainless steel, which limits the mesh size, and consequently limits the fineness of filtering. Known filter elements are relatively heavy, and manufacture thereof by being overmolded on the screen requires high temperatures of the order of 800°C, which gives rise to large amounts of energy expenditure and thus to a relatively high cost price. Finally, the structure of such elements does not lend itself to making elements that are not plane, for example elements that are conical . Consequently, an object of the present invention is to propose a filter element enabling the above technical problems to be solved. The invention achieves this object by the fact that each inside face and each outside face comprises at least sixteen angular sectors, each sector being formed by a free portion of screen, and in that the ratio of the free filter area of the screen over the total area of the element lies in the range 55% to 68%. According to another characteristic, each delivery passage includes a stiffening stud whose top end is in contact with the stiffening stud of the other element. According to yet another characteristic, each inside face and each outside face comprises at least four facing ribs that are diametrically opposite in pairs, each of which ribs has a bulge that is at least partially cylindrical and that is secured to the outer rim. According to yet another characteristic, the filter element is made of a thermoplastic material such as polyamide. According to another characteristic, the screen is made of a material such as polyamide or polyester with a mean mesh size of less than 20 µm. According to yet another characteristic, the screen is made of stainless steel. According to another characteristic, the filter element is in the form of a disk. In another variant, the filter element is conical in shape. While the screen is being back-washed, the filter element of the invention thus makes it possible to take a small number of angular sectors out of service at a time. In other words, by adopting the dispositions of the invention it is possible in a given amount of space to provide a filter that has better filtering efficiency than before, i.e. a filter capable of purifying or processing a volume of fluid greatar than the volume processed by prior filter elements. It should also be observed that this increase in filter efficiency is further improved by the fact that the surfaces of the screens situated between two consecutive radial ribs do not have any radial or annular reinforcement. The invention will be better understood and secondary characteristics and advantages thereof will appear on reading the following description and the accompanying drawings, in which: • Figure 1 is a front view of the inside face of the filter element of the invention; • Figure 2 is a front view of the outside face of the filter element; and • Figure 3 is a section view on line Ill-Ill of Figure 1 showing two filters assembled one against the other, each filter being made up of two filter elements. A filter element 1 of the invention is shown in Figures 1 and 2, which figures show respectively the inside face 2 and the outside face 3 of said filter element I. Thus, the filter element I which is in the form of a disk in this embodiment is defined axially by its two transverse faces, respectively its inside face 2 and its outside face 3. The filter element 1 is also defined radially by a peripheral outer rim 4 and by a central opening 16, the outline of the opening being defined by an inner rim 5 against which a rotary distributor of fluid to be purified comes into sliding contact after the filter element has been mounted in the filter block (not shown). A screen 6 is mounted between the outside face 3 and the inside face 2, and between the outer rim 4 and the inner rim 5, in such a manner that the screen 6 is parallel to the inside and outside faces 2 and 3. The inside face 2 of the filter element 1 also has radial ribs 72 that are regularly spaced apart interconnecting the inner and outer rims 4 and 5 to form angular sectors 21 in which the screen 6 presents a free filter surface. This surface is thus not encumbered by any reinforcement. The outside face 3 also has radial ribs 73 that are regularly spaced apart, extending in Register with the radial ribs 72 of the inside face 2 and thus interconnecting the inner and outer rims 5 and 4 to form angular sectors 31 in register with the angular sectors 21. The total thickness of the radial ribs 31 and 21 in register is equal to the complete thickness of the filter element 1. As can be seen in Figure 1, each angular sector 21 of the inside face 2 is provided on its outer rim 4 with a delivery passage 10 for delivering purified fluid and opening to the outside. Each delivery passage 10 also has a stud 11 whose top end lies in the plane common to the radial ribs 72 and the inner rim 5. Similarly, in Figure 2, each angular sector 31 of the outside face 3 is provided on its inner rim 5 with an admission passage 9 for the fluid to be filtered. It will be observed that there are as many angular sectors 21 on the inside face 2 as there are angular sectors 31 on the outside face 3, that these angular sectors 21 and 31 are sixteen in number, and that they are in register. Furthermore, at least four ribs 72 and 73, respectively on each of the inside face 2 and outside face 3 are provided with partially cylindrical bulges 13 secured to the outer rim 4. Naturally, the ribs 72 and 73 possessing these bulges 13 are placed in register with one another, and as can be seen from Figure 1, two I adjacent ribs 72 are provided at their bulges 13 with small tubular projections 19 having respective bores 20 passing therethrough. When two identical filter elements 1 are assembled inside face to inside face, each projection 19 is designed to engage in a complementary bore 14 formed in each bulge 13 of those two ribs 72 of the other filter element 1 that do not have projections 19. According to another advantageous characteristic, the filter element 1 is made by molding a plastics material such as polyamide, thereby making it more flexible and avoiding the formation of any swarf over the openings in the mesh of the screen 6 and making it possible to improve the filter efficiency of the filter element. Furthermore, this material also makes it possible to use screens made of polyamide or of polyester. Such screens have a mean mesh size of less than 20 µm, thereby making it possible to further improve the fineness of filtering. The operation of a filter block made up of two filters each made up of two filter elements 1 is explained below with reference to Figure 3. Two filter elements 1 are assembled together with their inside faces 2 placed facing each other, the projections 19 of one element being inserted in the bores 14 of the other element with radial interference. Each rib 72 of the inside face of one of the elements comes into leakproof contact with a facing rib 72 on the inside face 2 of the other element so that together with their screens 6 they define cells. These cells are made leakproof at their inner rims by the inner rims 5 of the filter elements 1 of a filter being put into contact with each other, and thus each delivery passage 10 of one of the elements is placed facing a delivery passage 10 of the other element so that together they form a delivery orifice 18. Since the radial width of the delivery passages 18 is relatively large in the peripheral outer rim 4, the stiffening studs 11 serve simultaneously to maintain leakproof contact between the outer rims 4 of the two outside faces 3 during juxtaposition of a plurality of filters, and also to keep the section of each delivery orifice 18 constant. As shown in Figure 3, two filters are juxtaposed firstly so as to associate the various angular sectors 21 and 31 and secondly so as to associate the bulges 13 of these elements. Thus, a fluid carrying impurities and to be filtered, is engaged in the feed duct formed by the central openings 16 of the various filter elements 1, and is conveyed (arrows F) via the admission passages 9 to the angular sectors 31 of the outside faces 3 of the various filter elements 1. The fluid situated adjacent to the outside faces 3 can escape only by passing through the screen 6 since the outer peripheral rims 4 of the outside faces 3 are in leakproof contact, thereby preventing the fluid from escaping directly. The liquid therefore passes through the screen 6 where it has its impurities removed, and passes through the cells 17 before leaving the filter via the delivery orifices 18. It should also be observed that since each filter element has sixteen angular sectors per outside face 3 and per inside face 2, it follows that when pairs of sectors 21 are obscured in succession at determined moments by a sectioning chamber (not shown) of a distributor of the fluid to be filtered and mounted to rotate coaxially in the central opening of two filters, the filter capacity of each filter is about 87.5%. Naturally, the filter block shown in Figure 3 could be constituted by a single filter made of two filter elements I, these filter elements having their outside faces 3 disposed in a case (not shown) in such a manner that the ar.gular sectors 31 form two admission half-chambers. Similarly, the filter element 1 can be frustoconical in shape with an inside face 2 parallel to the outside face 3. The invention is not limited to the embodiments described, but on the contrary covers all variants which could be applied thereto without going beyond its ambit or its spirit. WE CLAIM : 1. Filtering element provided with a central opening (16) and intended to be assembled with another element of the same type so as to form a filter, each filtering element (1) having two faces, insider (2) and outside (3) the filter respectively, each face comprising at least sixteen angular sectors (21, 31), each one being formed by a free portion of sieve (6), the surface of which has no reinforcement, an inner rim (5) delimiting the periphery of the central opening (16) and an outer peripheral rim (4), between which a sieve (6) is mounted parallel to said inner (2) and outer (3) faces, each face of the element further having radial ribs (72, 73) extending opposite each other between the outer (4) and inner (5) rims so as to form, on the inner (2) and outer (3) faces, angular sectors (21, 31), each rib (72) of the inner face (2) of one of the elements being able to come into contact with a rib (72) facing the inner face (2) of the other element so as to delimit cells (17) supplied on the one hand via inlet passages (9) made on the inner rim (5) of the sectors (31) of the outer face (3) of each element and opening outwards, on the other hand, via discharge passages (10) made on the outer rim (4) of the sectors (21) of the inner face (2) of each element, each discharge passage (10) of one of the elements being arranged facing a passage (10) of the other element, forming a discharge orifice (18), characterized in that each discharge passage (10) has a rigidification pin (11), the upper end of which is capable of coming into contact with the rigidification pin (11) of the other element.

Documents:

abstract.jpg

in-pct-2000-402-del-abstract.pdf

in-pct-2000-402-del-claims.pdf

in-pct-2000-402-del-correspondence-other.pdf

in-pct-2000-402-del-correspondence-po.pdf

in-pct-2000-402-del-description (complete).pdf

in-pct-2000-402-del-drawings.pdf

in-pct-2000-402-del-form-1.pdf

in-pct-2000-402-del-form-13.pdf

in-pct-2000-402-del-form-19.pdf

in-pct-2000-402-del-form-2.pdf

in-pct-2000-402-del-form-3.pdf

in-pct-2000-402-del-form-5.pdf

in-pct-2000-402-del-gpa.pdf

in-pct-2000-402-del-pct-409.pdf

in-pct-2000-402-del-petition-137.pdf