US 3793692 A
An improved filter for treating fluids utilizing a frame of unitary construction. The frame is constructed from a sheet of expanded substantially rigid material having solid sections disposed between sections of expanded material. The frame is adapted for folding into a box-like configuration with the solid portions forming end walls of the box. Filter media, such as fiberglas, is disposed within the enclosed box.
Description (OCR text may contain errors)
Unite States Patent 1191 v 1111 3,793,692
Tate et al. Feb. 26, 1974 FLUID TREATING FILTER 2,138,874 12/1938 Myers 55 1310. 31 2,597,927 5/1952 E d 55/528 x  Inventors: Tate; when Jackson 2,989,145 6 1961 0262;; 29/1635 F Louisville, y- 3,724,671 4/1973 Tate 5511310. 31  Assigneez American Air Film, Company Inc" 2,850,269 9/1958 Bohanon 55 519 Louisville, Ky.
22 Filed; Dem 2 1972 Primary ExaminerSamih N. Zaharna A r rE F.F.Cl tt' ] Appl- No 314,368 8818 an xammer ave 1 Related US. Application Data  Division of Ser. No. 111,303, Feb. l, 1971,  ABSTRACT abandoned.
An improved filter for treating fluids utilizing a frame  29/163'5 29/611, 55/518, of unitary construction. The frame is constructed from SS/DIG- 3 I 1 210/484 a sheet of expanded substantially rigid material having [Sl] Int. Cl. Bold 27/08 Solid Sections disposed between sections of expanded  Field of Search S5/DIG' material. The frame is adapted for folding into a box- 55/528; 29/163-5 210/484 485 like configuration with the solid portions forming end walls of the box. Filter media, such as fiberglas, is dis-  References Cited posed within the enclosed box.
UNITED STATES PATENTS 3,429,434 2/1969 Hickin 55/519 4 Claims, 8 Drawing Figures mammal 3.7s3,e92,
SHEET 1 UF 4 PAiimEnnzszsmm saw u or 4 INVENTOR. 205mm. uAcKsm BY JOHN 5 r 0% g, w flrromm I FLUID TREATING FILTER CROSS REFERENCE TO RELATED APPLICATIONS The present invention is a division of copending application, Ser. No. 111,303, filed Feb. I, 1971 by John E. Tate and Robert L. Jackson now abandoned.
BACKGROUND OF THE INVENTION In the conditioning of air in air conditioners, furnaces, and the like, the air to be processed is usually passed through a filter to remove particles of dust and other foreign matter. For many years filters utilizing fibrous material, such as fiberglas, as a filtering media have been used for removing these undesirable particles from the air. These filters come in many sizes and shapes and are constructed by many different methods. One of the most common type of filters in use today is one in which a basic core of continuous glass fibers bound together by a resinous coating is confined between two closely perforated sheets of bright brass. The perforated sheets are generally scrap from bottle plants and contain close circular orifices placed as closely together as possible. The circular orifices account for nearly 90% of the total she et area. The fiberglas media and the two closely perforated sheets of bright brass are held together by an inwardly facing U-channel constructed of fiber board or similar material. The side pieces of fiber board are either stapled together at their ends to hold them in tact with the perforated sheets or they are attached to the perforated sheets with an adhesive. Further, in some cases a narrowed metal strip is added to extend diagonally across each face of the perforated sheet to give extra strength.
SUMMARY OF THE INVENTION In the present invention, it is recognized that it is desirable to provide a filter for treating fluids which is inexpensive, more durable, and more easily fabricated than the filters prepared by the present accepted methods. Furthermore, it is desirable to have filters for fluid treating which have inherently increased strength within the filtering zone without requiring additional steps, such as, adding rigid strips diagonally across the face of the perforated sheets. It is also desirable to have a filter which has increased strength along its borders so that the filter will not weaken during heavy use.
The present invention advantageously provides a straight forward arrangement for manufacturing a filter for treating fluids which is economical, easily fabricated, and contains a minimum number of parts. The present invention further provides an improved frame for supporting filter media. The present invention also provides a filter for treating fluids having improved strength and durability in operating position.
Various other features of the present invention will become obvious to those skilled in the art upon reading the disclosure set forth hereinafter.
More particularly, the present invention provides a fluid treating filter comprising a filter media and a flowthrough box-like configured support frame of one piece integral and unitary construction framed as a unit to include fluid impervious end walls and integral front and back retaining screens, said frame being adapted to enclose said filter media. In addition the present invention may include sidewalls adapted to fit and engage said support frame.
It is to be understood that the description of the examples of the present invention given hereinafter are not by way of limitation and various modifications within the scope of the present invention will occur to those skilled in the art upon reading the disclosure set forth hereinafter.
Referring now to the Figures:
FIG. 1 is a perspective view of a filter of the present invention;
FIG. 2 is a perspective view of a unitary frame assembly according to one advantageous embodiment of the present invention prior to being folded into a box-like configuration;
FIG. 3 is a perspective view of a unitary frame assembly of FIG. 2 in a partially folded position;
FIG. 4 is an exploded perspective view of a filter of the present invention;
F IG. 5 is a perspective view of a unitary frame assembly of another embodiment of the present invention prior to being folded into a box-like configuration;
FIG. 6 is a perspective view of a unitary frame assembly of FIG. 5 in a partially folded position;
FIG. 7 discloses a schematic flow diagram of an inventive method for making a new and useful filter of the present invention; and,
FIG. 8 discloses a perspective schematic flow diagram for adding sides to a filter constructed according to the inventive method of FIG. 7.
Referring to FIG. 1 of the drawings, a filter assembly in accordance with one embodiment of the present invention is disclosed. The filter assembly includes a unitary frame assembly 1, filter media 3, and detachable sides 2 and 1 l. The frame assembly 1 is bent into a boxlike configuration with filter media 3 disposed within the confines of the box. Detachable sides 2 and 11 which advantageously are of U-shaped cross-section, are adapted to outer fit and enclose the sides of the unitary frame assembly I. A latch member 9, shown in the Figures as an indented tongue, is provided on the sides 2 and 11 for engaging groove 10 (FIG. 4) of the ends 7 and 8 (FIG. 4).
' The unitary frame assembly 1 is illustrated in FIG. 2 in unfolded form. The unitary frame assembly 1 includes solid ends 7 and 8 and retaining screens 4 and 6. The unitary frame assembly 1, as illustrated in the present embodiment, is a modification of a sheet of expanded metal wherein an expanded metal producing machine (not shown) has expanded only selected portions of a sheet of metal leaving other selected portions as solid metal. By selectively expanding only specific sections of the metal sheet and leaving other selected portions solid, a filter frame assembly having front and back retaining screens 4 and 6 with ends 7 and 8 is produced. In the illustration in FIGS. 2 and 3 the screens 4 and 6, and the ends 7 and 8 are constructed so that when bent at the junctions of the screens 4 and 6 with the ends 7 and 8, a box-like configuration is the result.
FIG. 3 illustrates the unitary frame assembly 1 in a position wherein the end 7 has been bent upwards at its juncture with screen 6 and end 8 has been bent upwards at its juncture with screen 6. Filter media 3, which advantageously can be of fiberglas and adapted to fit within the confines of the unitary frame assembly 1 when in a box-like configuration, is shown in place in the frame assembly 1 prior to the bending in a sidewards direction of screen 4 at its juncture with end 8.
The free edge of screen 4 is adapted to mate with the free edge of end 7, as illustrated in FIG. 4, when the unitary frame assembly 1 is bent into its box-like configuration. FIG. 4 further illustrates the engagement of the detachable sides 2 and 11 with frame assembly 1. Sides 2 and 11 are adapted to fit the frame assembly 1 and latch members 9 and grooves 10, as mentioned previously, are provided as the means for engaging and disengaging the sides 2 and 1] from the ends 7 and 8.
FIGS. 5 and 6 of the drawings illustrate another preferred unitary frame assembly 1 of the present invention. FIG. 5 illustrates the unitary frame assembly 1 in unfolded form. The unitary frame assembly 1 includes solid ends 7 and 8 and retaining screen 4 and 6. Screen 6 is further provided with extending sides 12.
FIG. 6 illustrates the unitary frame assembly 1 of FIG. 5 in a partially folded position wherein end 8 has been bent upwards at its juncture with screen 6, and extending sides 12 have been bent upwards at their juncture with screen 6. Filter media 3, adapted to fit within the confines of the unitary frame assembly 1 when in a box-like configuration, is shown in place in the frame assembly 1 prior to the bending in a sidewards direction of screen 4 at its juncture with end 8. The free edges of screen 4 are adapted to mate with the free edges of extending sides 12 and end 7 (not shown). Detachable sides 2 and 11 may be added to engage with frame as sembly 1 to give added support and rigidity to the sides.
Referring to FIG. 7 of the drawings, in carrying out the present invention, sheet metal is fed from roll 21 onto endless conveyor 22. Sheet metal from roll 21 is fed by conveyor 22 and guide rolls 23 to a metal expanding machine 24. Expanding die 26 is provided in machine 24 for expanding the metal. Further, expanding die 26 is set to raise at specifically set intervals so that at selected spacings on the sheet metal, the metal is left in tact as it passes under the die 26.
Expanded metal in the metal expanding machine 24 is then conveyed to a slitter 27 wherein the expanded metal is slit into sections of selected lengths. The expanded metal sections are then passed to a first forming machine 29. Guide rolls 28 are provided to guide the expanded metal sections into the machine 29 wherein upwardly extending ram 31, downwardly extending ram 32 and upwardly extending ram 33 form the expanding metal section into a semi-formed unitary frame I assembly. The semi-formed assembly is then transferred to endless conveyor 38 where it is conveyed to filter media adding means 34 wherein filter media is added to the semi-formed unitary frame assembly.
The assembly containing the filter media is then conveyed to a second forming machine 36 wherein horizontally extending ram 37 urges the vertically extending top section of the frame assembly into a horizontal position thereby completing the formation of a box-like frame with filter media confined therein.
FIG. 8 illustrates the addition of detachable sides to the filter product of FIG. 7 by transferring the filter product of FIG. 7 to endless conveyor 39 which in turn conveys the product to horizontally extending capping means 41 wherein detachable sides are added to the product.
Other modifications of the aforementioned method, such as adding filter media to the expanded metal prior to the first forming machine, and then forming the frame assembly in one step instead of two as illustrated, are contemplated without departing from the scope of the present invention. However, in practice, it has been found that semi-forming the assembly, then adding the filter media prior to the final forming step, is preferred since the semi-formed assembly lines up the sides and enables for easy addition of the 'filter media.
In the preparation of a filter of the instant invention, the unitary frame assembly 1 may be fabricated by modifying expanded metal as illustrated, as well as plastics and similar materials. Latch member 9, illustrated as a tongue in the aforementioned example, may be any means for engaging sides 2 and 11, such as, groove 10, with the assembly 1. Further, latching means may be provided for on the unitary frame assembly 1 instead of the sides 2 and 11 with a latch receiving means on the sides, without departing from the scope of the invention.
It will be realized that other changes may be made to the specific embodiment shown and described without departing from the principles and spirit of the present invention.
1. A method of making a fluid treating filter comprising the steps of: passing a sheet of metal through a means for expanding a selected portion of said sheet of metal; cutting said sheet to a desired configuration; adding a selected quantity of filter media to said cut sheet; and forming said sheet into a unitarily constructed box-like configuration, the selected expanded portions of said sheet being positioned as a back and front support for said filter media and the nonexpanded portion of said sheet being positioned as end walls for said filter media with a leading edge of said sheet abutting a trailing edge of said sheet.
2. A method of claim 1 including the step of adding side walls to said box-like configuration.
3. A method of making a fluid treating filter comprising the steps of: passing a sheet of metal through a means for expanding a selected portion of said sheet of metal; cutting said sheet to a configuration having two expanded sections and two solid sections, one of said solid sections being disposed between said expanded sections; forming said sheet into a unitarily constructed topless box-like configuration whereby one expanded section is a bottom, said solid sections are end walls, and the other expanded section is an extension of one of the end walls; adding a selected quantity of filter media to said formed sheet; and, forming a top for the box-like configuration whereby said expanded section which is an extension of one of the end walls is forced intqa horizontal position to form the top with a leading edge of said sheet abutting a trailing edge of said sheet.
4. A method of claim 3 including the step of adding side walls to said box-like configuration.
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