The grease filter is made with components that are secured together about the periphery of the filter by a seam with smooth surfaces. In one embodiment, the filter is constructed of three components, namely, a pair of plates and a rectagular or square frame. The peripheral edges of the plates and frame are interfolded on each other to form a rolled seam. The resulting structure is rigid and does not twist.
1. In a grease filter, the combination comprising
a plate having a plurality of pairs of spaced apart inwardly directed louvers defining a plurality of parallel passages for a flow of air and vapor therethrough; and
a frame disposed peripherally of said plate, said frame having an upper peripheral edge interfolded with a peripheral edge of said plate to define a seam thereat.
2. The combination as set forth in claim 1 wherein said frame has a plurality of apertures in at least one side thereof for passage of accumulated grease therethrough.
3. The combination as set forth in claim 1 wherein said plate is of rectangular shape.
4. The combination as set forth in claim 1 wherein each of said plate and said frame has a radiused corner.
5. The combination as set forth in claim 1 wherein said frame has a plurality of pairs of spaced apart inwardly directed louvers defining a plurality of parallel passages for a flow of air and vapor therethrough.
6. The combination as set forth in claim 5 wherein said passages in said frame are staggered relative to said passages in said plate.
7. A grease filter comprising
a front plate having a plurality of spaced apart parallel passages therein;
a back plate having a plurality of spaced apart parallel passages therein;
a rectangular frame disposed between and peripherally of said front plate and said back plate, said frame having an upper peripheral edge interfolded with a peripheral edge of said front plate to define a seam thereat and a lower peripheral edge interfolded with a peripheral edge of said back plate to define a seam thereat.
8. A grease filter as set forth in claim 7 wherein said passages in said front plate are staggered relative to said passages in said back plate.
9. A grease filter as set forth in claim 7 wherein said front plate has a plurality of pairs of inwardly directed louvers, each said pair of louvers defining a respective passage therebetween.
10. A grease filter as set forth in claim 7 wherein said frame is formed of a single strip of material having a pair of ends disposed in overlapping welded relation.
11. A grease filter as set forth in claim 7 wherein each of said front plate, back plate and frame is made of a material selected from the group consisting of aluminum, galvanized steel and stainless steel.
12. A grease filter as set forth in claim 7 wherein said frame has a plurality of apertures in at least one side thereof.
13. A grease filter as set forth in claim 7 wherein each said seam is characterized in having five layers of material of said respective plate and said frame defining a cross-section thereof.
14. A grease filter as set forth in claim 7 wherein said peripheral edge of said front plate is folded over said upper peripheral edge of said frame and said upper peripheral edge of said frame is folded on itself.
15. A grease filter as set forth in claim 14 wherein said peripheral edge of said back plate is folded over said lower peripheral edge of said frame and said lower peripheral edge of said frame is folded on itself.
16. A grease filter as set forth in claim 7 wherein each of said front plate and said back plate has a radiused corner.
17. The combination comprising
a first plate having an outwardly directed peripheral flange, a lip extending angularly from said flange, and a plurality of spaced apart parallel passages therein;
a second plate having an outwardly directed peripheral flange, a lip extending angularly from said flange, and a plurality of spaced apart parallel passages therein; and
a rectangular frame having a pair of flanges extending outwardly thereof whereby said flange of each said plate may be interfolded with a respective flange of said frame to form a seam to secure said respective plate to said frame to form a grease filter.
18. The combination as set forth in claim 17 wherein said first plate has a plurality of pairs of louvers therein, each said pair of louvers defining a respective one of said passages therein.
19. The combination as set forth in claim 18 wherein each said louver is corrugated.
20. The combination as set forth in claim 17 wherein said frame has a plurality of apertures in at least one side thereof.
21. A grease filter comprising
a first plate having a peripheral flange, a lip extending from said flange, and a plurality of spaced apart parallel passages therein;
a second plate having a peripheral flange, a lip from said flange, and a plurality of spaced apart parallel passages therein; and
a rectangular frame secured to and between said first plate and said second plate, said frame having a pair of flanges, each said flange of said frame being interfolded with said flange of a respective one of said first plate and said second plate to form a seam to secure said frame to each respective plate.
22. A grease filter as set forth in claim 21 wherein each said plate is of rectangular shape with radiused corners and includes a recess extending peripherally thereof adjacent said peripheral flange thereof.
23. A grease filter as set forth in claim 21 wherein each said seam is a rolled can style seam.
24. A grease filter as set forth in claim 21 wherein each of said first plate and said second plate has a plurality of pairs of louvers therein, each said pair of louvers defining a passage therebetween for a flow of air and vapor.
25. The combination as set forth in claim 24 wherein each said louver is corrugated.
26. The combination as set forth in claim 21 wherein said frame has a plurality of apertures in at least one side thereof.
27. In a method of forming a grease filter, the steps of
obtaining a plate having an outwardly directed peripheral flange, a lip extending angularly from said flange, and a plurality of spaced apart parallel passages therein;
obtaining a rectangular frame having a pair of flanges extending outwardly thereof;
placing said frame adjacent said plate with said flange of said frame opposite said flange of said plate; and
thereafter interfolding said flange of said frame with a respective lip and flange of said plate to form a seam to secure said frame to said plate.
28. A method of forming a grease filter comprising the steps of
obtaining a pair of plates, each said plate having an outwardly directed peripheral flange, a lip extending angularly from said flange, and a plurality of spaced apart parallel passages therein;
obtaining a rectangular frame having a pair of flanges extending outwardly thereof;
placing said frame between said pair of plates with each said flange of said frame opposite said flange of a respective plate; and
thereafter interfolding each said flange of said frame with a respective lip and flange of a respective plate to form a seam to secure said frame to said plates.