MXPA97005213A - Filtra element - Google Patents

Abstract

The present invention relates to a filter element for a fork assembly of an air filter system, the filter element is characterized in that it comprises: (a) first and second end caps having a filter medium positioned cylindrically, extending between the The filter medium is embedded within the first and second end caps, the filter medium positioned cylindrically defining a cylindrical interior in the filter element, (i) at least the first end cap comprises a smooth polymeric material that has a central air flow opening, (b) a cylindrical inner liner positioned to coat the cylindrical interior of the filter element, the inner liner extends over the first and second end caps, (c) a first slider construction; The sliding construction has a central mounting projection, the projection is positioned within the central flow opening of the air of the first end cap and within an inner diameter of the cylindrical inner liner, to slidably engage the fork assembly of an air filter system, and which is positioned between the fork assembly and both the inner liner and the first liner end cap, when the filter element is installed on the fork assembly; (i) the first slide construction comprises a rigid plastic construction; (ii) the first end cap has a first coefficient of friction and a first slide construction having a second coefficient of friction, the second coefficient of friction is smaller than the first coefficient of friction, and (iii) the first slide construction is a separate member of a cylindrical inner liner and the first polymeric end cap

Description

FILTERING ELEMENT Field of the Invention The present invention relates to filters for air, and in particular to filter elements for air.

Background of the Invention In many industries, filtration systems are used to filter particulate matter from air or process gases. For example, industrial processes can generate particulate matter that needs to be removed from the air in the factory. These filtration systems typically include at least one filter element, which contains a filter medium that is useful for entrapping the particulate matter. Examples of such filtering elements and are used are found in U.S. Pat. Nos. 4,209,310, 4,218,227, and 4,395,269. A wide variety of filter elements is known. In general, the filter elements have a limited life time during use. In other words, after a period of time, filter elements Ref. 025143 need to be removed and replaced. Once a filter element is replaced, the waste of the element used can be expensive and inefficient. Typically, the filtering elements used are transported for disposal to different places from where they are used. If a filter element used is contaminated with a hazardous material, then the waste in general is more complicated and expensive than if the filter element is contaminated with a non-hazardous material. For example, filter elements contaminated with hazardous materials usually can not be disposed of in a local public landfill. These filtering elements are typically disposed of in a public landfill for hazardous waste or by other means of disposal for hazardous materials. In general, industrial filter elements are large, bulky items that are difficult to transport. Due in part to its size and shape, as well as to the desire to control the contamination of the material collected on the filtering elements, it is a common procedure in these industries the use of such filtering elements "" to ship the industrial filter elements contaminated in drums of 0.206 cubic meters (55 gallons). Frequently the size of the filter element is such that only one can be transported per drum of 0.206 cubic meters (55 gallons). The cost of obtaining and transporting a drum or barrel of 0.206 cubic meters (55 gallons) for each filter element used can be expensive and ineffective in terms of cost.

Brief Description of the Invention as described in the Original Description of Priority U.S.

The invention described in the original description is directed to a filter element for assembly on a fork assembly included in an air filter system. The filter element generally includes an opening for air flow, central, and a first carriage or slide construction. The construction of the car or slide can be circular and is made of a hard, rigid plastic. The construction of the slide or carriage has a central mounting flange. This flange is positioned within the central air flow opening in such a way that it is oriented to slide over the fork assembly of an air filter system, when the filter element is installed on the fork mount . The flange for the central assembly may define a circular carriage or slide surface, which in general makes contact with the fork assembly when the filter element is slid on or out of the fork assembly. According to the original description, preferably a first carriage or slide construction is placed inside a first end cap of the filter element according to the invention. A second carriage or slide construction may also be located within a second end cap of the filter element. Preferably, the end caps are made of a polymeric, compressible, soft material. Preferably, the coefficient of friction of the end caps (ie, the coefficient of friction that they could exhibit if they were in sliding engagement: on the fork) is greater than the coefficient of friction of the surface of the car or slide, is say a part of the construction of the slide or carriage. The first end cap preferably has a sealing ring included therein. The sealing ring can generally have a triangular cross section.

Brief Description of the Improvements As a result of additional studies, some preferred constructs related to those of the U.S. original of the priority have been developed. Preferably, the filter elements are such that the sliding ring comprises a supporting construction, so that the filter element will substantially resist deformation of the circular in an amount of 1.27 cm (0.5 inches) or more, under a load of 22,675 kg. (50 pounds), and preferably 36.28-45.35 kg. (80-100 pounds) as described here. A possible, preferred support construction to be used for such purposes is a polymeric material filled with glass, more preferably a nylon filled with glass. Preferably the material is filled with glass to at least 15%, by weight, more preferably in approximately 20% -40% form. In this context, the resistance to deformation is proposed to be characterized when the load is conducted on the filter element which has been axially sealed to a surface such as a pipe sheet. The techniques for evaluating this are provided here. The techniques described here can be applied to a wide variety of filter elements. They are particularly well adapted, however, for use in elements which are cylindrical, with an external diameter of at least 25.4 cm (10 inches) (for the end cap of the complete filter element), the internal diameter of the less than 12.7 cm (5 inches) (for the opening of the air flow in the end cap) and a length of at least 25.4 cm (10 inches), and typically 50.8-76.2 cm (20-30 inches). For example, the external diameters of approximately 25.4-38.1 cm (10-15 inches), the internal diameters of approximately 12.7-25.4 cm (5-10 inches), and the lengths of approximately 50.8-76.2 cm (20-30 inches) they can be easily accommodated with the techniques described here. The application to other size elements, however, will be evident from the descriptions. Preferably, the filter elements include a sealing ring on an end cap, and in preferred systems the sealing ring is positioned at approximately 0.508-1.778 cm (0.2-0.7 inches) (typically 0.25-0.55 inches) from the first central opening of the seal. end cap, in a direction towards an outer periphery of the first end cap. This provides an effective and convenient seal in certain commercial systems, with an acceptable level of leakage risk. The dimensions recited above are 'developed particularly for the elements used in association' 'with the commercial units TORIT®, Downflo® and Downflo® II.

In the preferred arrangements, a second carrier construction or carriage construction is placed in the second end cap.

Brief Description of the Drawings In the drawings, where the like letters and reference numbers indicate corresponding elements in all the various views: Figure 1 is a schematic side elevational view, with portions removed by section, of a dust collector including the elements filtering agents according to the present invention; Figure 2 is a perspective view of a filter element according to a preferred embodiment of the invention; Figure 3 is a cross-sectional view taken generally along the line 3-3 in Figure 2; Figure 4 is an enlarged fragmentary view of a portion of Figure 3; Fig. 5 is a schematic, fragmentary, exploded perspective view showing the filter elements according to a preferred embodiment of the present invention, assembled in a dust collector; Figure 6 is a perspective view of a component of the filter element shown in Figure 2; Figure 7 is a bottom plan view of the component of Figure 6; Figure 8 is a top plan view of the component of Figure 6; Figure 9 is a schematic end view of a compressed filter element according to Figure 2; and Figure 10 is a fragmentary, enlarged cross-sectional view of a filter element according to a preferred embodiment of the present invention shown, schematically, in sealing combination with a structure, Figure 10 shows the filter element generally analogous to the figure 4; Figure 11 is a schematic perspective view of a filter element according to the present invention, with interrupted lines indicating a circumferential or peripheral area or region of 120 ° higher; Figure 12 is a fragmentary schematic view of a sheet metal sheet including an air outlet opening generally in accordance with a TORIT® Downflo® industrial filtration system, with dotted or interrupted lines indicating the positions of certain characteristics of the filter elements that could be associated with it, in use; Figure 13 is a view generally analogous to Figure 12, with dotted lines indicating the positions of the components under distortion; Figure 14 is a plan view of a support construction in accordance with the present invention and having a preferred configuration for use with a commercial Downflo® I filtering system. Fig. 15 is a fragmentary cross-sectional view taken generally along line 15-15, Fig. 14; Figure 16 is a fragmentary cross-sectional view taken generally along line 16-16, Figure 14; Fig. 17 is a fragmentary cross-sectional view taken generally along line 17-17, Fig. 14; Figure 18 is a plan view of a support construction in accordance with the present invention, configured for its purpose in the filter element of a Downflo® II commercial system; Figure 19 is a fragmentary cross-sectional view taken generally along the line 19-19, Figure 18; Figure 20 is a fragmentary cross-sectional view taken generally along the line 20-20, Figure 18; Figure 21 is a fragmentary cross-sectional view taken generally along the line 21-21, Figure 18; and Figure 22 is a fragmentary cross-sectional view generally analogous to the view of Figure 10, but showing the components preferably configured for a Downflo® II commercial system, wherein the support construction is configured as shown in the Figures. 18-21.

Detailed Description of the Description in U.S. No. 08 / 371,809 Some Problems with the Construction Materials in the Filtering Elements In many industries, systems for filtering air and / or other gases charged with dust or other particulate materials generated by industrial processes are necessary. Typically, these types of air cleaning systems or for dust collection include an outlet for clean air, an inlet for dirty air, at least one filter element, a housing for the filter element (s) (s). ), and constructions for mounting the element (s) to the housing. In some cases, arrangements for continuous cleaning (ie, periodic cleaning carried out without removing the filter element from the housing) are used. An example of a system for dust collection or air cleaning of this type is described in U.S. Pat. No. 4,218,227 (Patent 227), which was issued on August 19, 1980 to Robert E. Frey. The specification of the patent * 227 is incorporated herein for reference. To facilitate the use of air filters and filter elements in these and other air cleaning and dust collection systems, efforts have been made to reduce the size of the filters for the air and the filter elements without compromising the volume of the filter. gas that these elements and filters can handle in a short period of time. The elements and the extremely large filters are bulky and inconvenient to handle, and difficult to install and replace. "Examples of efforts to reduce the size of the elements and filters are described in US Patent No. 4,209,310 (the '310 patent), which was issued to James Berkhoel on June 24, 1980. The specification of the Patent 310 is incorporated herein for reference.These efforts to reduce the size of these industrial types of filter elements have been effective, but will still generally produce an element that is so large that a barrel of 0.206 cubic meters (55 gallons) is necessary. for the transportation of a single element In US Patent No. 4,395,269, which was issued on July 26, 1983 to Frederick Schuler and the specification of which is incorporated herein for reference, the use of the elements in accordance with the US Patent No. 4,209,310 is described.For installation, the filter elements are slid over a fork or fork mount, which provides the support for the elements in an assembly of the filter When a filter element needs to be replaced, it is removed from the fork assembly and discarded. The elements of the type described in the Patent U.S. No. 4,209,310 and U.S. Pat. No. 4,395,269, typically are not easily discarded, in part because they are not easy to compress for disposal. Consequently, the elements used are usually transported from the industrial environment to a disposal site in drums of 0.206 cubic meters (55 gallons). Typically, only one element is transportable by drum because the building materials included in each element care for or prevent the element from being easily compressed to conserve space. In many cases, the structural portions of the filter element which make it difficult to compress, are the end caps. In particular, many filter elements used in industrial filtration systems have metal end caps. The metal end caps are difficult to compress without specialized equipment capable of applying relatively high pressures. (A similar problem could be found if a rigid, hard plastic was used as the material of the extreme cover). It could be assumed that this problem of the metal end caps would be solved by providing a material of the end cap that was not as rigid as that of the metal end caps. However, there may be problems with this. In particular, when the filter element is slipped on and off a fork assembly, for example of the type described in US Pat. No. 4,395,269, the sliding action or assembly involves the sliding contact between the cap (s). (s) end (s) and fork mounting portions When both the end cap (s) and the fork mount portions engaged during the sliding action are made of metal (or hard plastic) ), the assembly or sliding is relatively easy to carry out, that is, the coefficient of friction between the metals of the end cap and the fork is generally low enough so that it can be easily overcome by the forces applied manually; that is to say, the portions of the end caps and the fork, which are coupled together during assembly, are generally smooth. However, if the metal of the end cap is replaced by a compressible, soft polymeric material, which can be easily compressed, the coupling during sliding or assembly between the filter element and the fork assembly involves a sliding coupling between the polymeric material and the material of the fork assembly. When the polymeric material is a soft rubber or rubber material; (1) The sliding coupling can easily damage the end cap; and (2) the rubber or rubber material will tend to provide a large coefficient of friction (with the fork) and will therefore resist slippage.

This can make the item very difficult to install and seal in place.

Some Advantageous Constructions of U.S. Serial No. 08 / 371,809.

In accordance with document U.S.S.N. 08 / 371,809, the preferred filter element constructions are provided. These preferred constructions are: (1) relatively easy to assemble on the fork assemblies, such as the type described in U.S. Pat. No. 4,395,269, wherein the portions of the filter element must slide along the fork portions during assembly, and (2) relatively easy to compress after use, for disposal. In particular, advantage is taken of the relatively soft, large friction polymer material in the end caps, with respect to its sealing ability, ease of construction, and ease of compression. At the same time, however, the filter element is provided with an arrangement so that the material of the relatively soft, compressible polymeric end cap is protected. of the sliding coupling with the portions of the fork or housing, when the elements are assembled and removed in the dust collectors.

In particularly preferred embodiments, filtering elements are provided which can be easily compressed in a factory or facility where they are used for filtration, without the use of special equipment for grinding, if desired. This is accommodated by providing materials, in a construction for the filtering elements, which can be compressed under the weight of an average worker. That is, they can easily be compressed simply by a worker who is standing or trampling the filter element. The specific constructions provided here, for example, can be easily compressed under the weight of a 68,025 kg worker. (150 pounds) while standing or jumping on the item. The reference numeral 1 in Figure 1 generally shows an industrial dust collector c air filtration system including filter elements according to the description of U.S.S.N. 08 / 371,809. Except that the filter elements are as described herein with respect to Figures 2-9, arrangement 1 may be generally as described in U.S. Pat. No. 4,395,269. Contaminated air or process gases are introduced into the dust collector 1 at the inlet for the dirty air 2, and the filtered air or gases leave collector 1 at the outlet for clean air 3. Figure 1 shows a view lateral with the portions of the housing 5 removed by cutting so that the filter elements 4 are observable. The majority of particulate matter filtered from the air or gases falls from the filter elements 4 and is collected in a funnel-shaped housing 5a for removal. In Figure 1, eight filter elements 4, two of which are sub-labeled as 4a and 4b, can be observed. The arrangement shown in Figure 1 is generally of the "forward flow" filtering elements 4. Accordingly, the air to be filtered is introduced to each filter element 4 by passage through a filter medium contained in the filter. same up to an open central portion of the filter element 4. The filter element 4 includes an opening for the air flow so that the air from the filter can exit the central portion. The stream of purified air on the end filter element is then directed to where desired, for example to the environment. Accordingly, for arrangements such as those shown in Figure 1, the contaminating material is generally collected on the external surface 6 of each filter element 4. It will be understood that the arrangement 1 of Figure 1 is schematic to show the placement of the filter elements 4, and details such as pulsed cleaning equipment are not shown. In generalWhen the pulsed cleaning equipment is used, periodically some of the particulate matter is removed by blowing each filter element 4, so that it falls into the funnel-shaped housing 5a. Still referring to Figure 1, it can easily be seen that the filter elements 4 are oriented in coaxially aligned pairs. For any given pair, for example the upper pair 7, access to the pair, for the removal of the arrangement 1, is obtained by means of a cover or fastener 8. In particular, to remove the pair 7 of filter elements of the arrangement 1, the bra or retainer 8 is removed. This will be better understood by reference to Figure 5. Referring to Figure 5, the pair of filter elements 7 is shown, in an exploded perspective view, in relation to the portions of the array 1 within which it is mentioned. In particular, the filter elements 4a and 4b are mounted on the fork assembly 9, and are retained thereon by the fastener 8. The fork assembly 9 is mounted on the surface of the housing 11, which is included in the housing 5. Specifically, the fork assembly 9 includes a threaded element 10 oriented for coupling into a threaded hole, unobservable, in the holder 8. During assembly, then, the fastener or retainer 8 it is tightened on the threaded post 10 sufficiently to fix or secure the filter elements 4a, 4b on the fork assembly 9, more particularly on the guide bars 12. The reference numeral 4a in figure 5 shows the element 4 which is adjacent to the housing 5 and to the surface 11 of the housing. The reference numeral 4b in Figure 5 shows the "element 4" which is adjacent to the fastener 8. Preferably, a sufficient force against the filter element 4b is provided by the fastener 8, to provide the sealing coupling between the elements 4a and 4b and also between the filter element 4a and the surface 11. Also, preferably the sealing coupling is provided between the holder or retainer 8 and the filter element 4b.Thus, the unfiltered air is prevented from being introduced into the filter element 4a. the central portions 13 and 14 of the filters 4a and 4b respectively.From a comparison of figures 1 and 5, it will be understood that during the assembly of the filter elements 4a and 4b, an operator might need to supply sufficient force to exceeding the coefficient of friction between the fork assembly 9 and the portions of the filter elements 4a and 4b which slidably engage the assembly of fork 9 when the installation is done. In particular, referring to Figure 1, the sliding action is directed upwards (i.e., the operator needs to push the filter elements 4 upwards, when they are being slid on the fork assembly 9). If the coefficient of friction between the filter elements 4a, 4b and the fork assembly 9 is relatively large, then the operator may need special equipment to push the elements 4a and 4b along the fork assembly 9 during assembly. Actually, if the friction was too great, damage to either the fork mount 9 or the filter element 4a, 4b could occur during assembly. Also, a relatively large coefficient of friction between the filter elements 4a, 4b and the fork assembly 9 can provide a difficulty in obtaining a good seal between: the elements 4a and 4b; the element 4a and the surface 11; and between the fastener or retainer 8 and the element 4b. That is, it could be difficult to provide sufficient compressive force by means of the retainer 8, to ensure a good seal where necessary. As will be understood from the detailed descriptions given below, for arrangements such as those shown in Figures 1 and 5, the necessary sealing couplings are provided by the axial forces directed between the fastener 8 and the surface 11, along the the direction of the shaft 15, which is shown in Figure 5. The compressive forces are then provided by the tightening of the fastener 8 in sufficient form so that the coefficient of friction between the filter elements 4a, 4b and the Fork mount 9 is overcome and control the axial compressive forces. That is, if the coefficient of friction between the filter elements 4a, 4b and the fork assembly 9 is too large, it could be difficult for the operator to tighten the fastener 8 in an amount sufficient to ensure a good seal. In conventional arrangements, the coupling between a filter element and the mounting of the fork is provided by the end caps of the filter element. Typically, the end caps each include a smooth inner edge or ridge that slides along the fork assembly during assembly. If, as in conventional arrangements, both the fork assembly and the end caps of the filter element "'are made of soft materials, such as a soft metal, then the sliding coupling is relatively easy because the coefficient of friction It is relatively low between the two, however, as indicated at the beginning, the filtering elements with metal end caps are difficult to compress, and it must be evident that if the filter element portion, for example the end cap, which the mounting of the fork during the sliding movement is of a soft polymeric material which exhibits a relatively large coefficient of friction, it may be difficult to mount the filter elements in their position, as will be evident from the descriptions with respect to Figures 2- 4 and 6-9, the preferred filter elements 4 are constructed so that: the soft polymeric material which is advantageous pair for compression purposes, be used in the end caps of the filter element; while, at the same time, a construction is provided to prevent the soft polymeric material from coming into contact, during the sliding engagement, with the fork assembly 9, in a manner that inhibits assembly of the elements 4. Referring to Figure 2, the filter element 4 is shown in perspective. The particular filter element 4 shown is generally a cylindrical filter element having first and second end caps 19 and 20, respectively, with the filter medium 21, which is shown in Figure 3, enclosed therebetween. The filter medium 21 can be any filtering medium usable in an industrial filter element. For example, the folded paper filter medium described in the '269 patent is usable in the invention. In general, for the arrangements shown in FIGS. 1 and 5, as indicated at the beginning, the filtering function is provided by directing the air to be filtered against the external surface 6 of the element 4. The air reaching the interior 27 of the filter element 4, then, has been filtered. The filter element 4 includes a flow opening 28 for the air, central, through which filtered air can pass. As will be seen in Figure 3, an opening 18 for air flow is provided in each end cap 19 and 20. The openings 28 are also provided for extending the portions of the fork assembly 9 therethrough during the assembly as best seen in figure 5. In figure 3, a cross-sectional view of the filter element 4 is provided. For the particular arrangement shown in Figures 2 and 3, the filter medium 21 comprises a cylindrical extension 24 of folded paper. The element 4 includes inner and outer liners 30 and 31, respectively. The inner and outer liners 30 and 31 extend between the end caps 19 and 20. The filter media 21 is placed between the inner and outer liners 30 and 31 in a conventional manner. In preferred constructions such as one shown in Figure 3, the inner and outer liners 30 and 31 comprise perforated materials well known in the filtering industry. Typically, these materials include perforated metal sheets or an expanded metal grid arranged or cylindrically placed. Still referring to Figure 3, the first end cap 19 encloses the end 35 of the medium 21. The end cap 19 comprises a polymeric material in which the fi brorant means 21 and the liners 30 and 31 are wrapped. In general, the polymeric materials included in the end cap 19 flow during the assembly of the filter element providing a connection between the components of the filter element in the vicinity of the end cap 19. The polymeric materials that can withstand the forces exerted on the end caps of A filter element while in use, which can maintain its integrity when exposed to contaminated air, and which can allow the filter element to be easily compressed (as described), are usable in the invention. In general, when the filter elements according to the present invention are described as "easily compressible" it is understood that they are compressed relatively easily under the forces generally applied perpendicular to a central longitudinal axis of the element.; that is, the forces directed along the direction of the arrows 39, figure 3. Preferably the element is such that the compression can be effected, if desired, simply by a person standing still, or by performing a trampling above, the element, although mechanical tablets could be used. It is preferred that the element be constructed of materials in such a way that compression occurs easily under forces easily applied by a 68,025 kg person. (150 pounds) standing on or trampling the element. Typically, the filter elements of the invention are also compressed in such a way that the size of the compressed filter (if "measured" in the direction in which compression forces are applied) is not greater than about one third of its original dimension.Therefore, if necessary, approximately three industrially sized filter elements, contaminated, can be transported in a barrel or drum of 0.206 cubic meters (55 gallons), while without compression, only an industrial-size filter element could be put inside a drum of 0.206 cubic meters (55 gallons) .A variety of polyurethanes, polypropylene, polyethylene , polyesters, nylons, polytetrafluoroethylene, polyvinylidene fluoride, polyamideimide and mixtures thereof, are polymeric materials usable for the end caps in the filter elements according to the invention.Preferably soft alveolar polyurethanes are used. Extreme 19 is a soft polymeric urethane material, such as BASF I-35453R blown resin of hydrofluorocarbon (HFC) available from BASF Corp. in Wyandotte, Michigan. It should be noted that a resin blown with water available from BASF having approximately the same density is also usable. In particular, the polyurethane used must be processed to a final product having a density when molded of approximately 224.46-357.72 kg./m3 (14-22 pounds / ft3) and a hardness of approximately 10 to 40, Shore A. Most preferred polyurethane comprises a material made with the resin I-35453R and isocyanate of I-3050U also available from BASF Corp. The materials should be mixed in a mixing ratio of 100 parts of resin 1-35453 with respect to 36.2 parts of isocyanate of I-3050U (by weight). Typically the relative density of resin 1-35453 is 1.04 (8.7 pounds / gallon), and for the isocyanate it is 1.20 (10 pounds / gallon). The materials are typically mixed with a high dynamic shear mixer. The temperatures of the components are typically approximately 21.1-35 ° C (70-95 ° F), and the mold temperature is typically approximately 46.1-57.2 ° C (115-135 ° F). For the particular arrangement shown in Figure 3, the end cap 19 includes the sealing ring 36. The sealing ring 36 extends outward (axially) from the first surface 37 of the first end cap 19. More specifically, preferably the sealing ring 36 is molded as a part of the first external surface 37. Collectively, the end cap 19, the filter medium 21, and an inner liner 30 define a central opening 38 (which comprises one of the openings 28, figure 3) . The filter element 4 includes, placed in the opening 37, the construction of the slide 40. The construction of the slide 40 can be better understood by reference to FIG. 4, an enlarged view of a portion of FIG. 3. Referring to Figure 4, the construction of the carriage or slide 40 includes a central mounting projection 41. The boss 41 of the central assembly is positioned within the opening 38 (which in part comprises one of the openings 28), and is oriented to provide a mating surface between the filter element 4 and the fork assembly 9, when the element The filter 4 is slid over the fork assembly 9 as best shown in FIG. 5. In particular, the central mounting boss 41 includes the surface 42 of the carriage or slide, which is oriented for the sliding coupling with the mounting 9 fork during assembly. For the arrangement shown, the surface 42 of the carriage or slide is circular (or annular) and is preferably constructed of a material which will have a relatively low coefficient of friction in sliding engagement with the fork assembly 9, to facilitate assembly and which will not be easily damaged by the sliding action. The sliding construction 40 can also function to facilitate the maintenance of the construction and the shape of the filter element 4. Without the sliding construction 40, the filter element 4 could deform and lose its shape. For example, some filter elements made of compressible materials could tend to deform while being transported, and during the installation and removal of the filter element. The sliding construction 40 can also function to provide support to the sealing ring 36 and to provide a better seal around the upper part of the folded filter medium 35. In some constructions of the filter element that do not have the sliding construction 40, the polymeric material capable of Flow that is included in the end caps, may not provide sufficient sealing around the top of the filter media, and therefore leakage around the insufficiently sealed area may occur. As it will be better understood from the above detailed descriptions, preferably the central mounting projection 41 is made of a hard plastic or polymeric material, such as polystyrene, so that the relatively hard, soft material functions as a sliding surface. or sliding "42. Typically and preferably, the construction of the full carriage or slide 40 will be molded from such material For such particular arrangement shown in Figure 4, the construction of the slide 40 includes the end 43 which is inserted or wrapped inside the end cap 19 during construction to secure or secure the construction of the slide or carriage 40 in place Figure 10 shows an enlarged fragmentary section analogous to that of Figure 4. Unlike Figure 4, however, Figure 10 shows a structure 44, such as a filtering element 4 or a surface 11, which is in sealing contact with the sealing ring. e 36, to show how the sealing ring operates. Structure 44 could be, for example: surface 11, figure 5; or one end of an adjacent filter element. As shown in Figure 10, the sealing ring is constructed in such a way that it can withstand the compressive forces performed when the filter elements 4 are mounted and secured in place on the fork assembly 9. In general, the sealing ring 36 is constructed so that it is properly compressed to form a good seal. The sealing ring 36 is preferably constructed in such a way that the compressive forces that have an effect on the sealing ring from the top 46 are dispersed throughout the base 47 of the sealing ring 36. (In the particular embodiment shown, the tip 46 It is rounded, it can be made, for example, as a circular radius For the example described below, it is made to correspond to a radius of 0.3175 cm (0.125 inches) The base 47 of the sealing ring 36 is preferably molded as a part of the end cap 19, therefore, when the compressive forces are dispersed throughout the base 47, they are absorbed by the end cap 19. However, the wide base 47 of the sealing ring 36, wherein the ring 36 engages the remainder of an end cap 19, ensures that the forces are widely dispersed in the end cap 19, so that they are not directed or focused too closely on the ends. holes of the filter medium 21 or of the liners 30 and 31. This helps to ensure structural integrity. As best seen in Figure 4, and described more fully below, the construction of the slide 40, and in particular the end 43, provides some lateral support for the sealing base 47. Referring to Figure 3, the filter element 4 includes a second end cap 20 which is analogous to the first end cap 19; however, for the particular element shown, the second end cap 20 does not have a sealing ring analogous to the ring 36. The second end cap 20 is sealed by any structure that secures the filter element 4 in place in the dust collector or in the air filtration system. For example, as shown in Figure 5, the filter element 4a is to be fixed or secured in place and thus sealed by the filter element 4b. Accordingly, the second end cap 20 of the filter element 4a is sealed by the sealing ring 36 of the filter element 4b (not observable in Figure 5). Therefore, it is not necessary for the second end cap that has a sealing ring. In the alternative, the filter element 4 can be fixed or secured in place (and therefore sealed) by an assurance mechanism included in the dust collector or filtration system. More particularly, as shown in Figure 5, the second end cap 20 of the filter element 4b is sealed by the fastener 8. The fastener 8 could either have a sealing ring attached thereto, or an O-ring. it could be provided between the fastener 8 and the element 46. Therefore, in general, for the particular embodiment shown it might not be necessary for the second end cap 20 to have a sealing ring. The second end cap 20 comprises a polymeric material in which the filter medium 21 and the liners 30 and 31 are wrapped. As with the first end cap 19, a preferred material for the end cap 20 is a soft polymeric polyurethane material. Actually, the same material can be used for both extreme lids. Referring to Figure 3, for the particular embodiment shown, collectively, the end cap 20, the filtering means 21, and the inner liner 30 define the opening 48 (which in part comprises one of the central openings 28, Figure 3). The filter element 4 includes, placed in the opening 48, the second construction of the carriage or slide 50. The construction of the carriage or slide 50 is analogous to the construction of the carriage or slide 40. Accordingly, the construction of the carriage or slide 50 includes a central mounting projection 51, placed inside the opening 48, and oriented to provide a sliding surface 52 for coupling between the filter element 4 and the fork assembly 9, when the element The filter 4 is slid over the fork assembly 9 as shown in FIG. 5. The sliding surface 52 is preferably constructed of a material as described for the sliding surface 42, which will have a relatively low coefficient of friction in the coupling with fork mount 9, to facilitate assembly. Really in the typical and preferred applications, the constructions of the carriage or slide 40 and 50 will be identical. In the preferred embodiments, the carriage or slide constructions 40 and 50 are constructions that are easily compressed or broken (under the lateral forces directed as shown by the arrows 39, FIG. 3) when the filter element 4 is compressed prior to disposal. . To facilitate rapid compressibility, the constructions 40 and 50 should be relatively thin and made of a material that allows the constructions 40, 50 to be easily compressed when the filter element 4 is compressed. In addition, the end caps 19 and 20 must also be made of materials and thicknesses that allow them to perform their own functions, but also allow them to be compressed when the filter element 4 is compressed prior to discarding. The materials described are appropriate for this. The construction of the carriage or slide 40, and by analogy the construction of the carriage or slide 50, are shown in greater detail in Figures 6-8. Figure 6 is a perspective view of the construction of the carriage or slide 40. Figure 7 is a bottom view of the construction of the carriage or slide 40, and Figure 8 is a top view of the construction of the carriage or slide 40. Figures 6 and 7 show that a preferred carriage or slide construction of the invention has spacers 54 adjacent to the central mounting boss 41 and on the underside of the lower surface 55. from a review of Figures 4 and 7, it will be evident how the separators 54 facilitate the production of the filter elements 4 of the present invention. In particular, the separators 54 will be coupled by the inner liner 30 during the molding process. In other words, when the end cap 19 is molded from a polymeric material, the construction of the carriage or slide 40 and the inner and outer liners 30 and 31 respectively will have been placed in the mold, in the company of the filter medium 21, and the polymeric material of the extreme cover. The separators 54 will support the liner 30 and prevent it from projecting through the polymer of the end cap when it hardens. A similar function is provided with respect to the filter paper 24 by the outermost projection or ring 56 on the construction of the carriage or slide 40. Referring to Figure 4, this external projection 56 is observable at the coupling end 35 of the cross section of the filter media 21. When the filter media 21 is the filter paper 24, the projection 56 will prevent the end 35 of the filter paper from falling through the end cap 19, when it is cured or hardened in the mold. Accordingly, the surface characteristics of the construction of the carriage or slide 40 facilitate the molding of the filter element 4 according to the present invention. In order to provide a broad base optimally to absorb the compressive forces that are discharged through the base 47, and to better facilitate the discharge of the compressive forces on the upper portion 46 of the sealing ring 36, applicants have found that the width of the cross section of the base 47 must be larger than the width of the cross section of the upper part 46 of the sealing ring 36. This difference in the widths of the cross section can be better observed in Figures 4 and 10. (The cross sections of many conventional sealing rings are either circular or rectangular. of circular cross section may provide an insufficiently broad base toward which the compressive forces are discharged while the sealing ring 36 is compressed). Alternatively, some conventional sealing rings can have a rectangular cross section, in which the cross section has a uniform width. Although this type of sealing ring could have a sufficiently wide base for the discharge of the compressive forces, the width of the upper part could be insufficiently narrow to focus the compressive forces of the contact point for sealing. More preferably, the sealing ring 36 has a triangular cross section to provide the advantages of both a broad base and a narrow top. More particularly, the width of the base 47 must be at least 1.27 cm (0.5 inches). Preferably a height to width ratio of at least 1: 1 is used. Actually, a 1: 1 ratio is preferred. The preferred triangular cross sections are generally ones in which the "sides" 60, 61 (Figure 4) extend upwardly at the same angle or inclination. For the preferred embodiment, in the described Example, an angle of 15.89 ° from the perpendicular was used. Furthermore, typically and preferably, the height of the ring 36 is such that it is compressed approximately 50% when compressed during air filtering operations. The height of the sealing ring 36 can be varied when necessary. However, for typical applications such as in the present application, the height of the sealing ring 36 when viewed as a cross section will be approximately 1.27 cm (0.50 inches). As previously described, it is convenient and advantageous to provide a filter element 4 that is easily compressible prior to disposal. This would allow more than one item to fit or fit in a 55-gallon barrel or drum. In addition, time and equipment could be saved if these filtering elements could be compressed by the weight of an average person. Therefore, more preferably, the filter elements can be compressed by a person weighing 68,025 kg. (150 pounds) or more. In Figure 9 an end view of the element 4 is shown after compression. The end cap 19, the construction of the slide 40, and the sealing ring 36 are all made of materials having thicknesses that allow these parts of the element to be easily compressed. It is to be understood that although numerous features and advantages of the invention have been described in the foregoing description along with the details of the structure and function of the invention, that the description is illustrative only. Changes may be made in the details, especially in the points of the form, size and arrangement of the parts within the principles of the invention to the extent "indicated" "by the broad general meaning of the terms in which the appended claims are expressed. For example, the filter elements of the invention do not necessarily have to be cylindrical as shown in the preferred embodiments in the Figures. In addition, the distances of the height and the external perimeter of the elements can be varied.

Example of document U.S.S.N. 08 / 371,809 The applicants constructed an industrial size, cylindrical filter element 4 of the invention, with the dimensions and materials as follows. This filter element 4 was 66.04 cm (26 inches) when measured from the upper surface 37 of the end cap 19 to the bottom of the second end cap 20. It was circular in cross section and had an external diameter of approximately 35.66 cm (14.04 inches). The upper and lower end caps 19 and 20 were cylindrical and molded from a polyurethane material including the BASF I-35453R hydrocarbon-blown resin, available from BASF Corp. Included in the upper end cap 19 was the sealing ring 36 , which had a triangular cross section. In addition, the distance from the base 47 of the sealing ring 36 to the upper part 46 of the sealing ring 36 was approximately 1.27 cm (half an inch). The ratio of the width of the base 47 to the height was 1: 1. A circular sliding construction 40 was placed in the central opening 38. This sliding construction 40 had a central mounting flange 41, circular and a carriage or slide surface 42. The protrusion had a thickness of 1.52 cm (0.6 inches) that tapers up to 0.0203 cm (0.008 inches) at the edge moving away from the end 43. The sliding construction 40 is placed in the central opening 28 such that the surface of the slide or carriage 42 contacts the fork assembly 9 when the element filter 4 slides on or off the fork assembly 9. The sliding construction 40 was also positioned in such a way that the first end cap 19 did not contact the fork assembly 9 when the filter element 4 slipped on or off the assembly of fork 9. The surface 42 of the car or slide was made of a material that allows the filter element 4 to slide easily on and out of the metal fork mount 9. In particular, a polystyrene was used. More specifically, the construction of the slide 40 was molded from grade 333 high impact polystyrene available from Huntsman Chemical Corporation. This high impact polystyrene had a hardness of approximately 15 Rockwell [M] (ie, on the Mohs scale), in accordance with the publicly available Huntsman product specification. The internal diameter of the boss 41 is used as a guide of the liner during the molding process of the middle liner face assembly.

Packed in the first end cap 19 were an inner liner 30, an outer liner 31, and a folded filter paper medium 24. The filter medium used was in some cases a cellulose and in other cases a synthetic medium made under the auspices of Donaldson. Co., Inc., and commercially referred to as Ultra Web® or Ultra-Tech®. The filter media 24 of folded paper was enclosed on one side by the inner liner 30, on the other side by the outer liner 31, on the upper part by the first end cap 19 and on the lower part by the second end cap 20. The second end cap 20 was analogous to the first end cap 19. However, the second end cap 20 does not have a sealing ring 36. The construction of the carriage or slide 50 was identical to the construction 40. The element was mounted on a system Downflo® or TD® filter, available from Donaldson Co., Inc., and found to work properly. More specifically, the filtering systems of the DF and DFT or TD 1150-6120 models can include the filtering elements of the invention.

Additional Discoveries and Improvements From the date of submission of the original application U.S. Priority, Serial No. 08 / 371,809, an additional evaluation and experimentation with the arrangements has been carried out in accordance with the principles described in the original description. These evaluations have led to certain additional recognitions of the preferred arrangements and the principles that relate to them. In this section, these evaluations and principles are addressed. As explained with respect to Figures 1-10, in many applications the filter elements according to the present invention will be cylindrical, with first and second end caps opposed. A sliding element, ring element or support construction 40, FIG. 3, according to the present invention, could be incorporated within each of the end caps, placed as described. In general, at least one of the end caps could include an annular sealing ring, such as the ring 36, figure 10, on it. In use, an element is sealed against the sheet for pipe or structure 11, figure 5, with the sealing ring 36 circumscribing a hole or outlet (opening) for air flow, in the pipe sheet. In figure 5 this is indicated by the positioning of the element 4a on the fork 12, with the individual poles of the fork 12 positioned around the outlet opening for clean air in the pipe sheet 11. In many conventional arrangements for the industrial filtration, the sheet for pipe or surface against which the filter element is sealed in use, is oriented either vertically, or at a slight angle from the vertical (as shown in Figure 1). Accordingly, the various filter elements mounted in association with the pipe sheet will be oriented either horizontally, or at a slight downward angle from the horizontal (Figure 1). In this "horizontal" context it refers to the direction of extension of a longitudinal central axis of the filter element, when a substantially cylindrical element is involved. Here the term "horizontal" will be used to describe the assembly of the elements on the vertical pipe sheets or the pipe sheets inclined slightly from the vertical, as in figure 1. Also in such arrangements, the entrance for the "air" "dirty" is often placed above the filter elements, ie in the upper part of the housing, for example as indicated in figure 1 in the reference number 2. This means that in general there will be a deviation or inclination of the load on the cylindrical filter elements, on the uppermost surface thereof, that is along a part of the external surface of the elements which is directed towards the inlet 2, during use. In general, it has been found that the particulate distribution on the charged filter element occurs with a larger load on a third of the outer circumferential surface of the cylindrical filter element, which is oriented and directed more directly towards the inlet for dirty air , higher. Therefore, in typical use, the filtering elements are not loaded uniformly, but instead with the highest amount of charge in this region. In Figure 11, a schematic view showing a cylindrical filter element 160 is shown. In the schematic view, the region shown by the numerical reference 161, and defined by dotted lines 62, indicates the radial section of 120 ° or higher 1/3, in which the majority of the load could occur, in the use . Such non-uniform loading on the filter elements tends to create tensile or shearing forces that deform the element from the circular cross-section. In addition, because the elements are mounted horizontally or substantially horizontally, the weight of the element, especially when it increases with the load, could tend to cause deformation from its original shape, even if the load were relatively uniform . If the element is substantially deformed from its original shape, leakage may occur in the seal between the element and the pipe sheet. One reason for this is that, when the element tends to deform from the circular, a portion of the sealing ring (illustrated in FIGS. 10 to 36) may tend to roll up and a leak may develop. In addition, if the sealing ring 36 circumscribes the air outlet in such a way that there is a relatively small distance between the portion of the pipe sheet coupled by the sealing ring and the opening in the pipe sheet for the clean air outlet, even a relatively small amount of deformation may be sufficient to overlap the sealing ring with the opening for the air outlet, with a concomitant seal failure. With respect to this, attention is directed to Figure 12. In Figure 12, a sketch showing the shape of an opening of the pipe sheet is provided in a conventional TORIT® Downflo® industrial filter housing, available from Donaldson Co., Minneapolis, MN 55440. The pipe sheet is indicated at 68. The opening 69 is defined by the straight sections 70 and the curved sections 71. The rods or guide posts for the fork support are indicated at 73, 74 and 75 respectively. In a conventional system, the curved section 78 could be the uppermost section, with the pipe sheet 68 which is oriented either vertically or substantially vertically. The pipe sheet 68 is a section of the wall indicated at 80 in Figure 1. Referring again to Figure 12, the circular region indicated at 85, ie between the lines 86 and 87, indicates the circular curve of the sealing ring 36 on the filter element, where it is pressed against the pipe sheet 68, for a seal. The distance between curve 87 and the edge of opening 69, ie, curve 78, is approximately 0.635-1.095 cm (0.25-0.75 inches) in a typical circumstance. Accordingly, in some cases if the filter element deforms sufficiently so that the sealing ring deforms from the curve 85 downwards by a distance of approximately 0.635-1.27 cm (0.25-0.5 inches), a leak will develop. In Figure 13, an example of such deformation is shown schematically, with region 96 between lines 91 and 92 reflecting the location of sealing ring 36 after deformation. In Figures 12 and 13, the reference number 100 indicates the outer periphery of the filter element 60, ie the outer periphery 301 of the end cap 19, Figure 3. It will be understood that the outer periphery 100 may suffer a distortion analogous to that of the sealing ring, as shown in region 101, figure 13. In general, it has been found that when the end caps of the filter element comprise the preferred soft polyurethane material as described above, and when the filter element is at least about 30.48-91.44 cm (1-3 feet) long, at least approximately 25.4-38.10 cm (10-15 inches) in the outer diameter and at least approximately 12.7-25.4 cm (5-10 inches) in internal diameter, and when the support structure or slip ring 40 (Figure 4) is molded from polystyrene as described above (and the surface 43 of the slip ring, Figure 4, is approximately 0.635-1.27 cm (0.25- 0.5 inches) wide and approximately 0.254-0.508 cm (0.10-0.2 inches) thick) if the filter element is mounted on a pipe sheet as illustrated in the schematic views of Figures 12 and 13, a leak can develop if the element is used in such. instant when your weight is increased substantially, for example 3-6 times. Accordingly, when the particular materials identified in this paragraph are used, a lifetime of use of the filter element, before it needs to be changed, may be shorter than what is most desirable. This does not mean that the filter element does not work well, it really can work very well. However, the life time of the filter element may be shorter than what is most desirable. further, dust collection systems of the type in which the filter elements according to the present invention are applied, are frequently industrial manufacturing operations involving hazardous materials. Many such operations involve cleaning the equipment using lead shot which is "applied as a jet" on the surface to be cleaned, and which is then pulled into the dust collection system to become charged on the filtering elements. This spent or exhausted shot is relatively heavy, and increases the weight of the filter element rather substantially, and in some cases for a relatively short period of time. This, in general, will aggravate the problem. Field tests with the TORIT® Downflo® units from Donaldson Co. (using approximately 66.04 cm (26 inches) in length, 27.94-33.02 cm (11-13 inches) in external diameter, approximately 21.59-24.13 cm ( 8.5-9.5 inches) of internal diameter) have suggested that the filter elements can accumulate contaminants in such a way that the weight of the filter will increase from approximately 5.9059 kg. (13 pounds) (clean) up to 36.28 kg. (80 pounds) (loaded), without the filter having achieved its final useful life. In such typical systems, end of life is often defined as use until the flow is restricted such that the pressure drop across the tubular sheet is 15.24-17.78 cm (6-7 inches) of water. In addition, field tests show that approximately 75% of the gained weight is distributed through a third of the top (120 radial degrees) of the filter, as described above with respect to Figure 11. For a commercial DITTM® Downflo® powder collector, the analysis showed that they could leak when the deflection of the filter could exceed approximately 1.27 cm (0.5 inches) down (figure 13) from its unloaded curve, given the location of the sealing ring on the test elements and the size of the opening for clean air in such systems. This deflection of 1.27 cm (0.5 inches) could be measured either by considering the distortion in the upper region 110 of the sealing ring 85, figures 12 and 13; or, considering the distortion in the upper region 111 of the outer periphery 100 of the filter element, figures 12 and 13; or both. As a result, it has been determined that the preferred design criteria for a filter element, especially one to be used in such a system, is such that the position of the sealing ring (or the outer periphery of the filter element) does not deform more than approximately 1.27 cm (0.5 inches) (when a load of 22.675 kg (50 pounds) is applied along a longitudinal upper third of the element) from its unloaded orientation, when the arrangement is sealed against a pipe sheet. In some relatively large, preferred arrays, the sealing ring 136 in certain preferred elements (Fig. 22) should be located about 0.254-0.762 cm (0.10-0.30 inches) or so from its location (where it is shown in Fig. 4). ) away from the inner hole 120 of the element 121, and towards its outer periphery 122. This is shown in Figure 22. In this context, the reference to the distance of the sealing ring from the inner bore 120 is understood to refer to the distance From the base or edge of the sealing ring where "the same engages the rest of the end cap, up to the edge of the internal hole." In figure 4, the internal hole is indicated at 300 and the outer periphery of the filter element is indicated in 301. Referring to Fig. 22, in such preferred embodiments of larger arrays, the projection, ring or pedestal 143 (or 43, Fig. 4) of the carriage or support construction 140 is pre-expanded. in its size, until it extends adjacent to the sealing ring 136. By increasing the outer diameter of the sealing ring 136 in this manner, it is moved a slightly larger distance from the opening for the air outlet in a sheet for typical TORIT® Downflo® pipe, so that the deformation which occurs during use, will probably be less to generate a leak. It is preferred that the construction of the slide 140 does not include a rigid component (the projection or pedestal 143) extending over more than about 25% of the width of the filter element, from the inner bore 121 to the outer periphery 122 (FIG. 11), so that it will not substantially resist compression under the force of approximately 68,025 kg. (150 pounds) as described above. Preferably the width of the pedestal or shelf 143 in the support construction 140 is within the range of 0.508 cm to 1.778 cm (0.2 to 0.7 inches); still more preferably 0.508 cm up to 1.27 cm (0.2-0.5 inches); and more preferably is not greater than 1016 to 1143 cm (0.4 to 0.45 inches).

It has also been found that to improve the resistance to deformation in use, without altering the ability to be compressed under a weight of 68.025 kg. (150 pounds) or by a person of 68,025 kg. (150 lbs) standing or trampling the element, it is preferred that a material somewhat stronger than polystyrene be used for the construction of carriage or corvee or support ring 40. Experiments with nylon filled with Glass have indicated that it is a preferred material today, although alternatives can be used. A material which has been found usable is nylon 6/6 filled with 20% glass (by weight) available from Bay Resin Co. of Millington, MD 21651, under the catalog # PA11G20. Experiments with nylon 6/6 filled with 40% glass from the same supplier have also been successful. In general, when such materials are used to form the support ring 140, they can be molded under the conditions specified by the supplier of the resin, without substantial variation. It is expected that in general polymers filled with at least 15% glass, and preferably filled with 20-40% glass, especially nylon, will be preferred. The home test methods were developed to determine the propensity to deformation. One test method used involved a computerized Sintech system, commercially available from Sintech Division of MTS Systems Corp., Stoughton, MA 02072. During the test, one element was slid over a tripod fork assembly analogous to a TORIT® Downflo assembly ®, where the three legs are located in positions 2:00, 6:00 and 10:00, as indicated in figures 12 and 13. The test element was observed to actually rest only in positions 2: 00 and 10:00 when the force was applied to the 1/3 upper part of the element. This generally simulates the forces found in a normal dust collector installation. During the test, the force was applied to the top of the element, that is, against the location or location 61 in figure 11. Both the force and the distance were automatically stored by the Sintech computer. When testing the element with respect to the element's compression forces, the tripod mount was removed and the entire filter compressed to 7.5 inches (7.5 inches) while strength levels are being recorded. The objective of these tests was to establish that the filter could be compressed without the necessary force exceeding approximately 68.025-90.70 kg. (150-200 pounds), at a final deflection of 19.05 cm (7.5 inches). The term "compressed to 19.05 cm (7.5 inches)" is meant to indicate that it was compressed sufficiently so that the "External Diameter" or thickness was 7.5 inches less than before compression. The design data suggests that the best total solution to improve the radial resistance of the filter, for the TORIT® Downflo® system, resulted from a focus on the insert ring or slide or slide construction 40 (or 140). The efforts were directed to the production of an insert 40 that could withstand at least 22.70 kg. (50 pounds) of longitudinal force along the upper third of the filter without a deflection of the sealing ring at this location (or alternately established, the outer flange of the filter element at this location) in an amount greater than 1.27 cm (0.5 inches), when the test was carried out. The nylon 6/6 filled with 20% glass, described above, was found to satisfy this. Additional tests were carried out on a commercial TORIT® Downflo® powder collector, model DFT2-8, from Donaldson Co., Inc. of Minneapolis, MN. The weight was applied to the filter element in increments of 4.54 kg. (10 pounds), in pesos of load on top of the filters. The deflection values were recorded. A design was considered preferred if the filter could hold up to 22,675 kg. (50 pounds) of the weight with a deflection of no more than 1.27 cm. { 0.5 inches). In this context, the term "a deflection of no more than 1.27 cm (0.5 inches)", refers to a deflection of a portion of the external protrusion (or sealing ring) of a filter element mounted substantially horizontally, downwardly , at its highest point under the load of 22,675 kg. (50 pounds), from its location when no load is applied. Preferably there is no such deflection (i.e. no more than one deflection of 1.27 cm (0.5 inches) to approximately 36.28 kg (80 pounds) of the applied force, and more preferably no deflection to approximately 45.35 kg. (100 pounds) of cargo. Of course, the arrangement must be such that it can still be easily compressed by a person weighing approximately 68,025-90.70 kg. (150-200 pounds).

Some Preferred Constructions Donaldson Company, Inc., the Assignee of the present invention, has developed preferred arrangements utilizing the principles described herein, for use in connection with its TORIT® Downflo® I and TORIT® Downflo® II industrial filtration systems. In both systems, the filter elements could preferably comprise the preferred inner liner, the outer liner, the filter material, and the soft polyurethane end cap material described above and in U.S. Serial No. 08 / 371,809. In the Downflo® I arrangement, a schematic view of which is shown in the original application in Figure 1, the outer edge of the sealing ring 36 could be located approximately 0.762 cm (0.3 inches) from the internal orifice of the filter element. The external diameter of the filter element could be approximately 27.94 cm (11 inches), and the internal diameter could be approximately 24.13 cm (9.5 inches). The length of the filter element is approximately 66.04 cm (26 inches). For such an arrangement, a preferred slide construction or inner ring construction is illustrated in Figures 14-17. The preferred features and dimensions are as described in the following two paragraphs. Referring to Figure 14, the construction 40 has an internal diameter of 21.41 cm (8.43 inches) and an outer diameter of approximately 22.86 cm (9.0 inches). Referring to the cross section of Figure 15, the width of the pedestal 200 is approximately 0.762 cm (0.3 inches), with the thickness of the pedestal, at 201, which is approximately 0.3175 cm (0.125 inches). The size or depth of the projection 202, which in use covers the inner hole of the end cap, is preferably approximately 1.27 cm (0.5 in) in shape. Referring to Figure 17, the thickness of section 210 is preferably approximately 1,524 cm (0.06 inches) in size, and section 211 is molded about 1.524 cm (0.06 inches) in radius. Preferably ring 40 of Figures 14-17 is molded from nylon 6/6 filled with 20% glass, as described above. The filter element for a construction Downflo® II has an internal diameter of approximately 2.54 cm (1 inch) larger, and is approximately the same length, as that of the filter element for Downflo® I. It typically has a larger external diameter, typically approximately of 35.56 cm (14 inches). Preferably, it is made of the same building materials as those identified as being preferred for Downflo® I, but with approximately the same internal diameter. Therefore, the protruding ring or pedestal of the component is approximately 0.3048 cm (0.12 inches) wider for the Downflo® II than for the Downflo® I, so that it is a little stronger.

In Figures 18-21, a preferred carriage or slide construction 140 for the Downflo® II is shown. The characteristics and dimensions are as follows: Referring to Figure 18, the internal diameter is approximately 23.9522 cm (9.43 inches). The outer diameter is approximately 26.01 cm (10.24 inches). Referring to Figure 19, the projection or pedestal 240 is approximately 1.0668 cm (0.42 inches) wide. The thickness in region 241 is approximately 0.3175 cm (0.125 inches); and the depth of the projection 242, which covers the inner hole of the end cap, is preferably approximately 1.27 cm (0.5 in) in shape. Referring to Figure 21, region 250 and structure 251 may be of the same thickness (and radius) as those associated with regions 210 and structure 211, of Figure 17. In general, from the above preferred descriptions and of the defined materials, it will be evident that in certain preferred arrangements according to the present invention, the following features are present: (1) Both end caps comprise a soft polyurethane material, or a similar material, which can be easily compressed. (2) Arrangements must be constructed from materials in such a way that they can be compressed under a person's weight of approximately 68,025 kg. (150 pounds) more or less, typically and preferably between a weight of 68,025-90.70 kg. (150-200 pounds) applied against the longitudinal axis of the filter element. (3) Preferably no rigid construction, but rather only the soft (compressible) polyurethane foam, or a similar soft material, extends completely through the end caps of the filter element from the inner bore, to the outer periphery. (4) Preferably the construction of the slide or inner ring (ie the ring 40 or 140 of the figures) is constructed of a material which provides sufficient resistance to the filter element against deformation, when about 22,675 kg. (50 pounds) are placed on a substantially horizontally mounted filter element, the upper surface of the filter element does not deform descending by more than about 1.27 cm (0.5 inch), and preferably the deformation is not greater than about 1.27 cm (0.5 inches) when approximately 36.28-45.35 kg. (80-100 pounds) of force are applied. (5) Although the construction of the ring may comprise a wide variety of materials, a preferred material is a nylon filled with glass, especially a nylon filled with 20% glass. %, as defined. (6) The arrangements preferably include a sealing ring molded as a part of one of the end caps, to function for axial sealing to a pipe sheet or similar structure.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having described the invention as above, property is claimed as contained in the following

Claims (22)

1. A filter element for mounting on a fork assembly of an air filtration system; The filter element is characterized in that it comprises: (a) first and second end caps (19, 20) having a cylindrically placed filter medium extending therebetween; the filter medium (21) is sandwiched within the first and second end caps (19, 29); the filter medium (21) placed cylindrically defines a cylindrical inner part in the filter element; (i) at least the first end cap (19) comprises a soft polymer material having an opening (38) for air flow, central; (b) a cylindrical inner liner (30), placed to cover the cylindrical exterior of the filter element; the inner liner (30) extends between the first and second end caps (19, 20); and (c) a first carriage or slide construction (40); the first carriage or slide construction (40) has a central mounting projection (41), the projection (41) is positioned within the airflow opening, central, of the first end cap (19) and within an inner diameter of the cylindrical inner liner (30), for slidably fitting the fork assembly (9) of an air filtration system, and for it to be placed between the fork assembly (9) and both the inner liner (30). ) as the first end cap (19), when the filter element is installed on the fork assembly (9); the construction of the carriage or slide (40) is a separate element of the cylindrical inner liner (30) and the first polymeric, soft end cap (19).

2. A filter element according to claim 1, characterized in that: (a) the first construction of the carriage or slide (40) comprises a rigid plastic construction.

3. A filter element according to claim 2, characterized in that: (a) the first end cap (19) has a first coefficient of friction and the first carriage or slide construction (40) has a second coefficient of friction; the second coefficient of friction is smaller than the first coefficient of friction.

4. A filter element according to claim 3, characterized in that: (a) the first carriage or slide construction (40) comprises polystyrene.

5. A filter element according to claim 3, characterized in that: (a) the first construction of the slide (40) includes an end portion (43) which is encapsulated or inserted into the first end cover (19).

6. A filter element according to claim 3, characterized in that: (a) the first end cap (19) includes an external surface having a sealing ring (36) thereon; the sealing ring (36) has a generally triangular cross section.

7. A filter element according to claim 6, characterized in that: (a) the sealing ring (36) is molded as a part of the first end cap (19).

8. A filter element according to claim 3, characterized in that: (a) the second end cap (20) comprises a soft polymeric material and has an opening (28) for air flow, central; and (b) the element includes a second carriage or slide construction (50); the second carriage or slide construction (50) has a central mounting projection (51), the projection (51) of the second carriage or slide construction (50) is positioned within the opening (28) for the flow of the air, central, of the second end cap (20) and within a diameter of the cylindrical inner liner (30), to slidely engage the fork mounting (9) of the air filtration system, and to be placed between the assembly of the fork (9) and both the inner lining (30) and the second end cap (20), when the filter element is installed on the fork assembly (9); (i) the second carriage or slide construction (50) comprises a rigid plastic construction; (ii) the second end cap (20) has a third coefficient of friction and the second construction of the carriage or slide (50) has a fourth coefficient of friction; the fourth coefficient of friction is smaller than the third coefficient of friction; and (ii) the second carriage or slide construction (50) is a separate element from the cylindrical inner liner (30) and from the second polymeric end cap (20).

9. A filter element according to claim 8, characterized in that: (a) the second construction of the carriage or slide (50) comprises polystyrene.

10. A filter element according to claim 8, characterized in that: (a) the second construction of the slide (50) includes an end portion which is encapsulated or inserted into the second end cover (20).

11. A filter element according to claim 1, characterized in that: (a) the first construction (40) of the carriage or slide, is sufficiently rigid to maintain the first end cap (19) substantially circular in its cross section, during use .

12. A filter element according to claim 1, characterized in that: (a) the first construction of the carriage or slide (40) includes an end ring (43); the end ring (43) extends partially, but not completely, through the first end cap (19) in a direction from the opening for the flow of the central air (38), towards an external cylindrical surface (6) of the element filtering (4).

13. A filter element according to claim 12, characterized in that: (a) the filter element (4) comprises a material in such a way that it will be compressed under the weight of a person of 68,025 kg. (150 pounds), when the compression is under forces directed against a portion of the cylindrical outer surface (6) of the filter element.

14. A filter element according to claim 1, characterized in that: (a) the first and second end caps (19, 20) consist essentially of a compressible polyurethane foam having a molded density of approximately 224.46-357.72 kg./m3 (14-22 pounds per cubic foot), and a hardness of approximately 10-40, Shore A.

15. A filter element according to claim 1, characterized in that: (a) the filter medium (21) comprises a folded paper medium.

16. A filter element according to claim 1, characterized in that: (a) the first end cap (19) includes an external surface having a sealing ring (36) thereon, molded as a part of the first end cap (19). ).

17. A filter element according to claim 16, characterized in that: (a) the sealing ring (36) includes a base (47) and an upper part (46); e (i) a width of the cross section of the base (47) is greater than a width of the cross section of the upper part (46).

18. A filter element according to claim 17, characterized in that; (a) the sealing ring (36) includes a generally triangular cross section that includes the base (47) and a pair of sides (60, 61) that meet at the top (46).

19. A filter element according to claim 18, characterized in that: (a) the base of the sealing ring (47) includes a width, and the sealing ring (36) defines a height extending from the base (47) to the part superior (46); and (b) a ratio of the height to the width that is approximately 1: 1.

20. A filter element according to claim 18, characterized in that: (a) each of the sides (60, 61) extends at an angle of approximately 15.89 ° from the perpendicular.

21. A filter element according to claim 1, characterized in that: (a) the central mounting projection (41) includes an internal diameter of approximately 21.41 cm (8.43 inches), and an outer diameter of approximately 22.86 cm (9.0 inches) ).

22. A filter element according to claim 21, characterized in that: (a) the central mounting projection (41) comprises polystyrene.