Flexible Sheet Type Maintained In Nonplanar Configuration Patents (Class 55/500)
  • Patent number: 4488966
    Abstract: This invention comprehends a new and unique means for preventing the crowns (forward projections of the pleats) of a backflushable filter element from splitting due to the cyclic action that is experienced during cleaning and backflushing. In one embodiment, a plurality of spacers, preferably wedge shape, is positioned between the outwardly projecting pleats of the filter media thereby preventing the splitting thereof. A plurality of spacers may also be placed between the inwardly projecting pleats to provide additional support during the cleaning and backflushing cycle. In another embodiment a ring is placed adjacent the inwardly directed pleats and the inner end cap lip; this also prevents splitting of the crowns when the filter element is subjected to the cyclic action of cleaning and backflushing.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: December 18, 1984
    Assignee: Brunswick Corporation
    Inventor: John I. Schaeffer
  • Patent number: 4477272
    Abstract: A filter used in conjunction with a motor driven fan is mounted on the cage which covers the fan blades. The filter has a configuration similar to that of the cage and has a slot extending from its outer periphery to its central area to permit the filter to be slipped over the motor. Drawstrings are sewn into the filter about its outer periphery and are used to secure the filter to the cage. One end of each drawstring is rigidly connected to one of the corners of the slot and the other end of each drawstring has a hook which is hooked onto a bar of the cage to hold the drawstring taut. The cage and filter are disposed on the intake side of the fan so that the air is filtered before it impinges on the fan blades. This prevents the accumulation of dust and dirt on the fan.
    Type: Grant
    Filed: July 6, 1982
    Date of Patent: October 16, 1984
    Inventors: Craig E. Hollis, Glenn E. Hollis
  • Patent number: 4455823
    Abstract: A diesel exhaust particulate trap is provided with a heat resistant particulate filter which includes a perforated and pleated metal substrate member coated with a ceramic fiber filter material on its interior surface so as to define a filter chamber for the inside-out flow of exhaust gases through the filter. In a preferred embodiment, an electrical particulate filter igniter is associated with the filter. The igniter includes a trap door pivotably secured to the substrate member, which is normally biased to a closed position by a spring but which can be opened by exhaust flow prior to an accumulation of particulates on the filter. Opening and closing of the trap door is used to effect deenergization and energization, respectively, of an electrical heating element used to initiate combustion of particulates.
    Type: Grant
    Filed: October 20, 1982
    Date of Patent: June 26, 1984
    Assignee: General Motors Corporation
    Inventors: Kenneth B. Bly, Otto A. Ludecke, Richard H. Smith
  • Patent number: 4452619
    Abstract: A pleated media filter element is disclosed which includes pleat spacers which are an integral structural part of the pleated media. The construction of the pleat spacers is accomplished by scoring on the unfolded media a continuous line pattern upon the portion of the media which, when folded, forms a pleat tip of the element. When the scored media is folded into pleats the patterns each define areas on the respective pleat tips which are integral structural parts of the media itself. The configuration of the pattern causes a portion of the media at the pleat tip to project transversely relative to the respective pleat, serving thereby as an integral spacer to space the pleat apart from the pleats on either side thereof.
    Type: Grant
    Filed: June 18, 1982
    Date of Patent: June 5, 1984
    Assignee: Donaldson Company, Inc.
    Inventors: Mervin E. Wright, Sheila C. Peyraud, Bradley B. Nielsen
  • Patent number: 4449993
    Abstract: A filter module comprises a frame bridged by a plurality of spaced-apart arch members, on which is supported a one-piece filter element comprising a plurality of pockets which each enshroud an arch member, and which connect into a mouth portion circumscribing the frame and held in position by a drawstring. The filter module is easily erected, and a seal between the inlet and outlet sides of filter equipment employing the module is easily provided.
    Type: Grant
    Filed: July 19, 1982
    Date of Patent: May 22, 1984
    Assignee: Equifab, Inc.
    Inventor: Willard Bergeron
  • Patent number: 4445912
    Abstract: Effluent with entrained particles is drawn through a filter module (A) by an exhaust blower (B). The filter module includes an inertial separator (C) for providing an inertial separation of particles from the effluent air and a plurality of filter cartridges (D) which allow air to pass therethrough but not particles. A plenum E interconnects the filter cartridges with the exhaust blower to channel the filtered air from the filter module to the exhaust blower. A flow controller (F) controls the flow rate of air through each of the filter cartridges maintaining it substantially constant. The flow controller includes a flow rate sensor for sensing the flow rate through each filter cartridge and a butterfly damper blade for selectively restricting the plenum to maintain the flow rate substantially constant. A filter cartridge cleaner (G) is selectively actuated when the flow controller is unable to maintain a preselected minimum flow rate.
    Type: Grant
    Filed: February 4, 1982
    Date of Patent: May 1, 1984
    Assignee: The Mike Volk Co., Inc.
    Inventors: Michael Volk, David A. Metzger, Donald H. Ostby, Robert R. Ostby
  • Patent number: 4412849
    Abstract: A method and apparatus (1) for control of airborne particulates in enclosed spaces, wherein air is made to flow in parallel airstreams (F), with velocities of the streams selectively graded across the work space (W), so that the integrity of the air flow pattern is better preserved while encountering obstructing objects (6) that lie in its path; and so that any particle introduced into a stream remains entrained and airborne over a longer distance along the clean-to-dirty axis (X). The velocity gradient is achieved by a filtering device (1) comprising a plurality of pleats (25) each pleat having a different surface area.
    Type: Grant
    Filed: November 20, 1981
    Date of Patent: November 1, 1983
    Assignee: Klenzaids Engineers Private Limited
    Inventor: Chandru M. Shahani
  • Patent number: 4378980
    Abstract: A gas borne particle filtering apparatus having a filter medium (13) with inlet and outlet openings (11, 12) in a staggered sawtooth cross-sectional configuration (140, 141) in a casing (10) for the filter medium positioned such that the gas passes along and between the sawteeth on both sides of the filter medium is described. A screened belt or support (14) for the filter medium is described. The apparatus is particularly suited to cleaning heated or cooled air in a confined work space in a factory containing small micron sized particles so that the air can be recycled.
    Type: Grant
    Filed: November 9, 1981
    Date of Patent: April 5, 1983
    Assignee: James M. Hammond
    Inventor: James Long
  • Patent number: 4363643
    Abstract: A filter assembly in an air cleaner includes a lower wire-form adapted to receive two opposite ends of a pliable filter material. Spaced wires on the lower wire-form enable manual forming of pleats in the filter material and define the tops of such pleats. A complementary upper wire-form is engageable with the lower wire-form and attached filter to define the bottoms of such pleats.
    Type: Grant
    Filed: October 16, 1981
    Date of Patent: December 14, 1982
    Assignee: Emerson Electric Co.
    Inventors: Clifford B. Elbrader, Jimmy L. Milum
  • Patent number: 4360433
    Abstract: A self-supporting tubular fibrous filter element consists of elongated fibers compacted in a direction parallel to the central axis of said tubular element to have a substantially constant density throughout the length and thickness of the tube with a majority of the fibers in parallel to one another in a circumferential direction about the said axis. When required, a perforated cylindrical support sheet is molded into at least one cylindrical face of the element.
    Type: Grant
    Filed: February 18, 1981
    Date of Patent: November 23, 1982
    Assignee: Process Scientific Innovations Limited
    Inventors: Brian Walker, Kenneth Merrie
  • Patent number: 4357150
    Abstract: An improved high-efficiency electrostatic air filter device which has a high efficiency of dust collection and a long service life. The device is composed of a charging section having a plurality pairs of electrodes to charge the dust particles in the gas to be treated; and a dust collecting section which is provided with a corrugated filter medium and spacer electrodes that are disposed in the troughs of the corrugations of the filter medium, and one of each pair of the electrodes in the charging section and the specer electrodes on one side of the filter medium in the dust collecting section are applied with high electric voltage.
    Type: Grant
    Filed: February 5, 1981
    Date of Patent: November 2, 1982
    Assignee: Midori Anzen Co., Ltd.
    Inventors: Senichi Masuda, Naoki Sugita
  • Patent number: 4343631
    Abstract: Filtration system configurations particularly useful for cleaning high temperature raw gas containing fine particulates such as that discharged from coal gasification and fluidized bed combustion processes. Thin filter elements, having elongated clean channels on one side of a gas permeable ceramic membrane and shorter dirty channels on the other side, extend radially outward from a central duct. Raw gas flows about and through the filter elements, and clean gas which permeates the membrane enters the duct. The elements are cleaned by a back pulse of clean air, spitting the particulates to the bottom of the containing vessel and through an outlet. A high density filter packing within a containing pressure vessel is achieved by nesting a plurality of the duct and filter element modules, or through other orientations and filter element configurations.
    Type: Grant
    Filed: January 30, 1981
    Date of Patent: August 10, 1982
    Assignee: Westinghouse Electric Corp.
    Inventor: David F. Ciliberti
  • Patent number: 4292061
    Abstract: An air filter assembly for a fuel-injected engine of the rectangular air inlet type typical of some imported automobiles is secured directly to the filter seat flange of the air intake opening of the engine, without a separate housing or canister. The filtering element is of a soft, porous foam material backed by a wire mesh of relatively large mesh size, and a collar at the base of the filter assembly is secured to both the filtering element and the backing mesh to hold the assembly together and in the proper configuration. Backing may be included on both the inner and the outer sides of the filtering element, sandwiched between inner and outer bands or flanges of the collar, with fasteners extending between the bands to pull them together and hold the filtering element and backing in the collar. The filtering element and backing are formed into an outwardly bulging, generally arcuate configuration for optimizing filtering area.
    Type: Grant
    Filed: April 25, 1980
    Date of Patent: September 29, 1981
    Inventor: Charles M. Land
  • Patent number: 4290263
    Abstract: A diesel particulate trapping and incineration system including a porous wall monolithic ceramic filter element having dual open-ended inlet passages separated from adjacent exhaust passages by particulate filtering porous walls. A balancing system for the distribution and incineration of particulates is provided including dual inlet ducts feeding exhaust gases to both ends of the inlet passages and valve means for controlling the amount of inlet gas flow entering the open opposite ends of the inlet ducts. In this way control is obtained of distribution of particulates over the length of the inlet duct walls as well as of the incineration of particulates upon heating of the exhaust gases to incineration temperature.
    Type: Grant
    Filed: December 12, 1979
    Date of Patent: September 22, 1981
    Assignee: General Motors Corporation
    Inventors: Gamdur S. Mann, Dilip V. Tendulkar, William J. Parker
  • Patent number: 4277264
    Abstract: A cleaning arrangement for a pleated filter includes opposite blower and suction heads parallel to the pleats that move in tandem to effect cleaning. In the preferred embodiment, the heads have air slots that are effectively as wide as a single pleat, the blower slot extends substantially across the entire filter, and the suction slot has two sections that each extend halfway across the filter with the sections being respectively operative as the heads move back and forth.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: July 7, 1981
    Assignee: Schomann, Inc.
    Inventors: Kenneth M. Buchholz, Henry T. Le Maire
  • Patent number: 4236901
    Abstract: A cylinder primary air filter element is coaxially disposed within a cylindrical shell between an air intake pipe and an outlet provided in the shell. A resilient secondary air filter element is deformably secured in an opening formed in a sidewall of the shell so as to be located outside the outer periphery of the primary air filter. The secondary filter element is secured in place by a filter element retaining plate which is arcuately shaped so as to be concentric with the primary filter element and is readily detachably attached to the shell. A sufficiently enlarged air flow passageway is thus defined between the outer periphery of the primary air filter element and the filter element retaining plate and consequently the resistance encountered by the air flowing through this passageway may be considerably reduced and the excessive bulging of the air cleaner may be avoided. A reed valve assembly is connected to the outlet of a housing which surrounds the secondary filter element.
    Type: Grant
    Filed: December 18, 1978
    Date of Patent: December 2, 1980
    Assignees: Nippondenso Co., Ltd., Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Yasutosi Kato, Hideo Kamo, Tadashi Ogawa, Kazuhiko Ito, Katsuziro Sato, Tatsuo Asai
  • Patent number: 4233040
    Abstract: The engine of a self-propelled combine is mounted in an enclosure having an inlet through which cooling air is drawn by an engine-driven fan. The air is filtered by a rotating disk-like screen mounted over the air inlet before passing through a radiator adjacent the inlet. A duct extends across the face of the disk from its center to periphery, changes direction and terminates with an open end adjacent the inlet side of the fan by-passing the radiator. The duct is also open adjacent the face of the screen so that the fan draws air through the duct, (some of the air being necessarily drawn from inside the screen as it passes the duct opening) so that foreign material filtered from the mass of cooling air being drawn through the unobstructed portion of the screen and held on the screen exterior surface is removed and carried through the duct. A trash knife rigidly attached to the periphery of the screen extends outwards parallel to the screen's axis of rotation.
    Type: Grant
    Filed: July 5, 1978
    Date of Patent: November 11, 1980
    Assignee: Deere & Company
    Inventors: Bernard F. Vogelaar, Bruce L. Warman, James R. Nelson
  • Patent number: 4227953
    Abstract: High efficiency air filters are fabricated by forming two end assemblies from rectangular wall members with side plates attached to extend upwardly from opposite sides thereof. A removable wall of expendable material such as ordinary masking tape is applied to the other two sides, extending between the ends of the side plates to form a shallow pan which is filled with a liquid adhesive. The pleated filter media is attached along its two side edges to side wall members having notched ends for mating with the side plates of the end assemblies. One edge of the filter media between the two side walls is immersed in the pool of adhesive and the side walls are attached to the side plates. After the adhesive hardens, the masking tape is removed and the other end assembly is attached in the same manner.
    Type: Grant
    Filed: December 2, 1977
    Date of Patent: October 14, 1980
    Assignee: Cambridge Filter Corp.
    Inventors: Stanley J. Wasielewski, Stephen M. Hladik
  • Patent number: 4213771
    Abstract: A pocket filter in the form of a filtering block is provided with an assembly of channels open at one end to receive gas from which dust is to be removed, and is interleaved with the channels of another assembly open towards the other end and delivering the gas from which the dust has been removed. These channels have a generally square-shaped cross-section, and are connected to each other, for example by stitching lines, along their edges. During operation, the initial shape provided for the cross-section of the channels of the two above mentioned assemblies is maintained by tensioning these two assemblies with tensioners or the like, on which are fixed the edges of the outer channels of the filtering block.
    Type: Grant
    Filed: July 3, 1978
    Date of Patent: July 22, 1980
    Assignee: Air Industrie
    Inventor: Jean-Pierre Guibet
  • Patent number: 4200444
    Abstract: Gas filtration apparatus comprises a filter element mounted in a casing having an inlet and an outlet so disposed that gas flowing from inlet to outlet is constrained to pass through the filter element, an audible warning device operable by gas flowing through the inlet and means responsive to the difference between the gas pressure at the inlet and the gas pressure at the outlet and arranged to cause the audible warning device to operate whenever said difference exceeds a predetermined value.
    Type: Grant
    Filed: March 14, 1975
    Date of Patent: April 29, 1980
    Assignee: Engineering Components Limited
    Inventor: Stanley P. Witchell
  • Patent number: 4154688
    Abstract: A corrugated tubular filter element is provided, resistant to corrugation collapse under high differential pressure, although formed of filter sheet material susceptible to such collapse, comprising, in combination, filter sheet material enclosed in a dual layer of more open foraminous sheet material and formed in a closed corrugated configuration having axial corrugation folds arranged in groups with adjacent side surfaces in supporting contact with each other; and, interposed between said groups, solid wedge support elements extending axially of the corrugation folds from end to end of the element having side surfaces in supporting contact with external side surfaces of the end folds of each group, substantially filling the spaces between the end folds of adjacent groups, and confining the folds of each group in substantially parallel array against lateral movement; and a foraminous support sheath disposed at least one of externally and internally of the filter sheet material in supporting contact with adja
    Type: Grant
    Filed: January 27, 1978
    Date of Patent: May 15, 1979
    Assignee: Pall Corporation
    Inventor: David B. Pall
  • Patent number: 4149862
    Abstract: An internal combustion engine exhaust gas filtering device in which an elongated high temperature resistant filter cartridge, gas permeable from end to end and radially, is received within a sheet metal casing having gas inlet and gas outlet ends with the filter cartridge spaced from the gas inlet end to form an entering exhaust gas distributing plenum, the filter cartridge being spaced from the casing internal side walls by an elongated circumferential spacing member which forms gas passages along the length of the filter cartridge which are open toward the filter cartridge but are closed toward the casing internal side walls whereby the exhaust gas to be filtered can flow longitudinally into the filter cartridge from the entering gas plenum and can flow radially from the passages in the spacing member into the filter cartridge, the spacing member also acting to protect the sheet metal casing against high temperature corrosive action of the exhaust gases.
    Type: Grant
    Filed: June 22, 1978
    Date of Patent: April 17, 1979
    Inventor: Robert R. Sewell, Sr.
  • Patent number: 4147524
    Abstract: A plurality of laterally spaced parallel tapes extend along each side of a strip of filter material in engagement with it, and the sheets and tapes are in accordion folded form so that there is a stack of integrally connected parallel filter sheets spaced apart by the portions of the tapes between them. Each tape has at its side of the stack exposed portions, along which a line of hardened adhesive extends to connect them and form a stiffening band, whereby there are parallel stiffening bands extending across each side of the stack of filter sheets.
    Type: Grant
    Filed: April 24, 1978
    Date of Patent: April 3, 1979
    Assignee: Mine Safety Appliances Company
    Inventors: Wayne L. Smith, Roger P. Wolf
  • Patent number: 4133661
    Abstract: The drawings illustrate an air filter assembly which is assembled from a pair of identical box-like housing halves. Equally spaced rib elements are formed in each half such that, upon assembly, the rib elements are interdigitated to provide a space for confining therebetween a pleated filtering sheet having a large filtering area.
    Type: Grant
    Filed: November 25, 1977
    Date of Patent: January 9, 1979
    Assignee: General Motors Corporation
    Inventor: Ronald L. Strnad
  • Patent number: 4129428
    Abstract: A bag-type filter having a removable filter element, said element being mounted in a cassette frame which may be inserted and removed from the filter housing. The filter element has a plurality of tubular sleeves which are open at the top and closed at the bottom to provide elongated gas passsageways surrounded by filter material. The cassette frame includes stiffening members positioned within said sleeves and a rectangular frame surrounding the top of the filter element. The filter element is suspended from said rectangular frame and is releasably clamped to the frame. The cassette frame has a lower structure which may support the cassette outside the housing and provide reinforcement for the cassette. The filter element is clamped to the frame portion of the cassette by collar means extending from the open top of the filter element over the frame portion, and locking rods operable to interlock the collars with the frame portion of the cassette.
    Type: Grant
    Filed: August 29, 1977
    Date of Patent: December 12, 1978
    Assignee: Aktiebolgatet Svenska Flaktfabriken
    Inventors: Rune S. Andersson, Svante O. Berglund
  • Patent number: 4124362
    Abstract: A filter assembly including a filter frame with filter media disposed therein and a border flange arranged to engage the edge of the filter frame, the border frame being clamped to the frame by a deformable resilient clamp which is inserted between the filter frame and the flange.
    Type: Grant
    Filed: July 18, 1977
    Date of Patent: November 7, 1978
    Assignee: American Air Filter Company, Inc.
    Inventors: Karl L. Westlin, Herbert V. Cork, Jr.
  • Patent number: 4123240
    Abstract: A means for preventing weld splatter produced during the welding together of two housing parts from entering a fluid passageway contained within the housing. The preventing means comprises an annular chamber located between the fluid passageway and the surfaces to be welded together and a screen contained within the chamber to cover a vent passage connecting the chamber to the fluid passageway. The screen prevents weld splatter from passing through the vent passage into the fluid passageway where it may later contaminate the fluid flowing therethrough.
    Type: Grant
    Filed: June 14, 1977
    Date of Patent: October 31, 1978
    Assignee: Parker-Hannifin Corporation
    Inventors: Michael A. Keresman, Curtis H. Schueuerman
  • Patent number: 4123239
    Abstract: A bag-type filter having a removable filter element, said element being mounted in a cassette frame which may be inserted and removed from the filter housing. The filter element has a plurality of tubular sleeves which are open at the top and closed at the bottom to provide elongated gas passageways surrounded by filter material. The cassette frame includes stiffening members positioned within said sleeves and a rectangular frame surrounding the top of the filter element. The filter element is suspended from said rectangular frame and is releasably clamped to the frame. The cassette frame has a lower structure which may support the cassette outside the housing and provide reinforcement for the cassette. The stiffening members include elements engaged in the sleeves to hold them open, the elements comprising a wire lattice having offset guide portions adapted to engage in the closed bottoms of the sleeves.
    Type: Grant
    Filed: August 29, 1977
    Date of Patent: October 31, 1978
    Assignee: Aktiebolgatet Svenska Flaktfabriken
    Inventors: Rune S. Andersson, Svante O. Berglund
  • Patent number: 4080185
    Abstract: Across the gas flow path in a duct such as for air conditioning there is placed a composite filter set comprising a plurality of filter elements and means joining said elements, each of said filter elements comprising a plurality of filter pockets and a frame holding said pockets at their open ends, and said joining means connecting the frames of adjacent filter elements in a manner to form a gas-tight seal therebetween so that flowing gas can advance only by passage through one of said filter pockets.
    Type: Grant
    Filed: September 16, 1976
    Date of Patent: March 21, 1978
    Assignee: Firma Carl Freudenberg
    Inventors: Joachim Richter, Kurt Huber, Rolf Schneider, Peter Rutsch
  • Patent number: 4056375
    Abstract: A gas filter element comprising a holding frame and a plurality of self-supporting wedge-shaped filter pockets each having its wide end open and secured to said frame, each element comprising a pair of substantially symmetrical pocket halves secured to one another along the wedge edge and centrally along the opposite wedge end faces, and a plurality of laminar spacing elements with each pocket extending from adjacent the open end toward the wedge edge, each spacing element being secured to the opposite inclined wedge faces, each filter pocket being rendered self-supporting by the securing of the sub-elements to one another and the securing of the spacing elements to the pocket. Advantageously the filter pockets each comprises fusible fibers, the pocket halves being joined to one another by fusion and the spacing elements being secured to the pocket by fusion.
    Type: Grant
    Filed: September 3, 1976
    Date of Patent: November 1, 1977
    Assignee: Firma Carl Freudenberg
    Inventors: Wolfgang Ringel, Peter Rutsch, Rolf Schneider, Edgar Kohl
  • Patent number: 4018686
    Abstract: A fluid strainer element capable of withstanding high differential pressures when used and which facilitates straining of fluid flowing through the continuous side wall and one end wall of the element. The strainer is generally cup-shaped and includes an inner cup-shaped support structure having staggered perforations extending through the surfaces thereof. An outer cup-shaped strainer structure constructed of wire mesh is closely received over the support structure with the open ends of the two structures being substantially coextensive with each other. An annular binding ring is closely received over the structure open ends and is rigidly affixed thereto. The mesh size of the straining structure may be varied as is desired and/or necessary for any use and normal fluid flow through the strainer is from outside to inside the element.
    Type: Grant
    Filed: July 10, 1975
    Date of Patent: April 19, 1977
    Assignee: Nupro Company
    Inventors: Earl D. Shufflebarger, Edward E. Kish, Frank M. Cunningham, John R. Boylan, Donald J. Murauskas
  • Patent number: 4014796
    Abstract: Disclosed are a strainer and a method of injection-moulding the strainer of plastics. A strainer according to this invention comprises a pair of semi-cylindric shells integrally and movably connected along their adjacent longitudinal sides in the state of being developed; top and bottom circular boards integrally connected to the top and bottom frames of one of said semi-cylindric shells; and nets integrally connected to each of said semi-cylindric shells. This developed structure of the strainer makes it possible to injection-mould a semi-product of strainer as a whole in a single injection-mould die, and a so moulded and developed strainer is easily assembled in the final and complete cylindric shape by simply closing the semi-cylindric shells and integrally connecting them along their abutting longitudinal sides.
    Type: Grant
    Filed: June 6, 1975
    Date of Patent: March 29, 1977
    Assignees: Yamakawa Industry Company Ltd., Nifco Inc.
    Inventors: Masaaki Sugiyama, Takuo Yuda, Akira Mizusawa
  • Patent number: 3961924
    Abstract: A self contained filter assembly for cleaning air and gas which is light-weight, inexpensive and easily disposable. The filter assembly includes a housing having walls formed of corrugated cardboard. A paper filter element in the form of a paper web is positioned in the housing and is folded in an accordian-like manner to form a plurality of web portions. The web portions form pockets which alternately open in the direction of flow of the air or gas being cleaned. Spacer elements positioned in the web pockets are fastened to the side walls of the housing to reinforce the housing and to counteract outwardly and inwardly lateral forces acting on the housing walls. The spacer elements also are shaped to resist bending along their lengths and to absorb tensile and compression forces occurring in the direction of flow of the air through the housing.
    Type: Grant
    Filed: February 20, 1975
    Date of Patent: June 8, 1976
    Assignee: AB Lectrostatic
    Inventor: Magnus Alskog
  • Patent number: 3941571
    Abstract: A filter pleat fold spacer for use in a gas filter device of the type having a flow-through filter frame and a pleated filter media disposed within the frame to hold the pleats of the filter media apart when subjected to the flow of gas to be filtered, the pleat spacer being formed to provide a yieldable surface adjacent the pleat fold turns of the media.
    Type: Grant
    Filed: April 7, 1975
    Date of Patent: March 2, 1976
    Assignee: American Air Filter Company, Inc.
    Inventor: Allan R. Getzin