Air Filter Arrangement

Abstract

An air filter arrangement incorporates a replaceable pleated air filter element which is installed in a rectangular frame. The air filter element is collapsible by flattening together the pleats and placed in an opening in the frame and thereafter stretched apart to extend across the space opposite frame sides and held in that position, by a magnetic element on the end pleat at either end of the air filter element. Sealing pads made of a material similar to the filter element panels are secured to the other two opposite frame sides which engage respective opposite ends of the air filter element for reducing air flow around the pleat ends. A planar lattice restraint is held in a perimeter slot extending around the frame opening to prevent contact of the air filter element and the lattice restraint to minimize the risk of holes being torn in the filter element by such contact.

Claims

1. An air filter arrangement comprising: an open rectangular frame comprised of four frame sides joined together and defining a frame opening; an air filter element comprised of a pleated sheet of porous material at a respective ends, said together making up said air filter element able to be expanded by pulling said pleats apart to fill said frame; a magnetic element attached to each pleats at either end of said air filter element magnetically attracted to a first pair of opposite frame sides to hold said air filter element in an expanded state drawn across said frame opening.

2. The air filter arrangement according to claim 1 further including a filter element lattice restraint held within said frame opening on one side of said expanded air filter element and secured therein.

3. The air filter arrangement according to claim 2 wherein a slot is defined on one side of each of said frame four sides receiving perimeter edges of said lattice restraints with said air filter element spaced outside said slot to minimize contact therebetween.

4. The air filter arrangement according to claim 3 wherein each of said slots are formed by a removable L shaped sheet piece having one leg thereof positioned against the inside of an associated frame side and a second leg thereof projecting out into said opening parallel with but spaced to one side of said frame side so as together define said slot therebetween with said lattice restraint held therein.

5. The air filter according to claim 3 wherein said frame sides are molded with said slot defined to the inside thereof.

6. The air filter arrangement according to claim 1 wherein a fibrous sealing pad is secured against an inside surface of each of a second pair of opposite frame sides whereat ends of said pleats are juxtaposed to be in contact therewith and thereby block air from flowing around the ends of said pleats of said air filter element.

7. The air filter arrangement according to claim 6 wherein said fibrous material of said fibrous sealing pads are made of a substantially similar material from which said air filter element is made.

8. The air filter arrangement according to claim 5 wherein said frame sides are molded from a plastic material and a magnetic portion is attached to said first pair of opposite frame sides adjacent said magnetic elements to attract a respective magnetic element to hold said air filter element in an expanded state extending across said frame opening.

9. The air filter arrangement according to claim 1 wherein each of said frame sides are of a channel shape and said pleats at either end of said air filter element are received within said channel shape of said first pair of opposite frame sides and said sealing pads are mounted to a bottom wall of said channel shape of said second pair of opposite frame sides.

10. A method of mounting a replaceable and expandable pleated air filter element in a rectangular frame opening made up of four U-shaped frame sides defining a rectangular opening comprising inserting said air filter element in a collapsed state with pleats thereof flattened together into said opening; expanding said air filter element to locate a pleat on each end against a respective one of opposite frame sides and detachably connect the same thereto.

11. The method according to claim 10 wherein said end pleats are detachably connected to said frame sides by a magnetic attraction force.

Description

DESCRIPTION OF THE DRAWING FIGURES

[0018] FIG. 1 is a pictorial view of an air filter arrangement according to the present invention disposed in a horizontal position.

[0019] FIG. 2 is an enlarged fragmentary sectional view of a corner portion of the air filter arrangement shown in FIG. 1 with the air filter element partially folded up within a frame.

[0020] FIG. 3 is an enlarged fragmentary sectional view of a corner of the air filter arrangement shown in FIG. 1 but in an upright vertical position and with the air filter element removed.

[0021] FIG. 4 is a fragmentary sectional view of a corner of the air filter arrangement shown in FIG. 1 in a horizontal orientation along a direction defined by the length of the pleats of the air filter element.

[0022] FIG. 5 is a fragmentary sectional view of an air filter arrangement along a direction normal to the pleats of the filter element.

[0023] FIG. 6 is a fragmentary sectional view of an air filter arrangement of an alternative embodiment thereof in a direction parallel to the pleats of the filter element.

[0024] FIG. 7 is a fragmentary sectional view of the air filter arrangement shown in FIG. 6 in a horizontal orientation but from a direction normal to the length of the pleats of the air filter element.

DETAILED DESCRIPTION

[0025] In the following detailed description, certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims.

[0026] Referring to the drawings and particularly FIG. 1, the air filter arrangement 10 according to the invention is comprised of a rectangular formed steel open frame 12 and a pleated filter element 14 installed therein and formed from a porous fibrous sheet material. The frame 12 is made up of opposite pairs of sides 16, 18, each comprised of channels of a formed metal construction.

[0027] The pleated filter element 14 is collapsible into a stack of layers by folding the pleats 19 flat together, greatly reducing their volume for storage and shipping. The pleats 19 are shown in a partially folded up condition in FIG. 2.

[0028] The pleats 19 are captured between the channel legs 20 of the first pair of opposite frame sides 18.

[0029] To install the air filter element 14, the pleats 19 are folded flat together to form a compact stack of pleat sides. The collapsed air filter element 14 can then be angled to be inserted within the opening 15 defined by the frame and within the space defined by the channel 20 of the pairs of sides 16, 18 and then straightened out to be captured therein. The pleats 19 are then pulled apart to be opened to completely occupy in opening of the frame 12 by the air filter element 14, bringing the last pleat at either end 19A (FIG. 2) and 19B (FIG. 4) against a flange portion 22A, and an L shaped piece 22 thereafter installed against the bottom wall 24 of the sides 16.

[0030] Each end pleat 19A, 19B has a magnetized strip 26 attached thereto which is attracted to the main wall 22A of the L shaped piece 22 and the wall 24 of the sides 16 to be securely held thereagainst to stabilize the filter element 14 in its expanded state and completely extending across the frame opening 15.

[0031] This completes the installation of the air filter element 14 in the frame 12.

[0032] The removable L shaped pieces 28 each have a main portion 28A and a flange 28B installed to be disposed against each inside wall of frame sides 18 (FIGS. 2, 3).

[0033] The sides 22A, 28B of the pieces 28 overlap slightly in the corners as seen in FIG. 3.

[0034] The pairs of sides 22B, 28B overlie the insides of a lattice restraint 30 to protect the filter element 14 from any contact therewith which could cause a tearing of the filter element 14.

[0035] The lattice restraints 30 are shown somewhat diagrammatically as having substantial thickness in FIGS. 4-7 for clarity, but are preferably of a flat configuration as seen in FIGS. 2 and 3.

[0036] The frame 12 side members 16, 18 may also be made as aluminum extrusions with an integral slot 38 for the lattice restraint 30, which is thereby permanently held in the frame 12 similar to the molded plastic construction shown in FIGS. 6 and 7.

[0037] As mentioned, the sides of the frame 12A can also be made of a molded plastic construction as shown in FIGS. 6 and 7.

[0038] In this case, a magnetic piece 36 is attached to the bottom inside surface of the frame sides 16A so as to create an attraction to the magnetic strip 26 on the filter element end pleats 19A, 19B to hold the end pleats 19A, 19B against the frame members 16A and thereby hold the filter element 14 completely occupying the opening 15 in the frame 12 in the expanded condition.

[0039] The slot 38 for the lattice restraint 30A (which can be made of plastic or netting) is created by an inner molded wall 40 in each of the wall sides 16A and 42 in sides 18A.

[0040] A sealing panel is mounted to the side 18A as in the first described embodiment, in order to minimize any air flow around the ends of the pleats 19, comprised of a pad 32 of fibrous material preferably similar to the material from which the filter element 14 is made, which is installed on the inside of each of the frame members 18 so as to engage the ends of the pleats 19. The ends of the pleats 19 engage the pad 32 and tend to become interconnected to minimize air flow past the ends of the pleats 19.