Filter paper cup for a percolator and process for making the same

• US 4,094,234 A
• Filed: 05/13/1976
• Issued: 06/13/1978
• Est. Priority Date: 05/13/1976
• Status: Expired due to Term

• Current Assignee: James River Corporation of Virginia (KOCH Industries Incorporated)
• Original Assignee: Brown & Company PLC
• Inventors: Wright, Robert G., Olney, Wallace E.
• Primary Examiner(s): Sever, Frank
• Application Number:
  US05/686,111
• Time in Patent Office: 761 Days
• Field of Search: 210/493 R, 210/483, 210/500 R, 210/503-505, 210/506-508, 428/35, 428/153, 162/111, 162/113, 99/295, 99/306, 99/310, 93/86, 264/163, 264/82, 426/433, 426/77-84
• US Class Current: 99/310
• CPC Class Codes: A47J 31/08 Paper filter inlays therefor to be disposed after use
• CPC Class Codes: B31B 2100/00 Rigid or semi-rigid containers made by folding single-piece sheets, blanks or webs
• CPC Class Codes: B31B 2100/0024 having all side walls attached to the bottom
• CPC Class Codes: B31B 2110/10 having a cross section of varying size or shape, e.g. conical or pyramidal
• CPC Class Codes: B31B 2110/20 having a curved cross section, e.g. circular
• CPC Class Codes: B31B 2120/70 having corrugated or pleated walls
• CPC Class Codes: Y10S 493/941 Filter
• CPC Class Codes: Y10T 428/1303 Paper containing [e.g., paperboard, cardboard, fiberboard, etc.]
• CPC Class Codes: Y10T 428/24455 Paper

Abstract

A percolator having a cylindrical basket concentric with a wand is provided with a filter paper cup having an annular bottom coextensive with the bottom of the basket and having upstanding fluted sides, characterized in that the flutes are steam and heat set. The filter cups are formed by cutting and forming them into a nest of cups having an imporforate bottom, heating the nested cups, exposing them to moist steam, heating to dry the steamed cups, and cooling them to ambient temperature, transferring the nest of cups to a frusto-conical die having a circular top commensurate with the circular bottom of the filter cups, a central die-hole, and outwardly and downwardly flaring sides corresponding to the natural outward flare of the nested cups, and punching an axial hole in said nested cups while on said die by means of a punch complementary with said die-hole.

Claims

1. In a percolator for brewing coffee comprising a cylindrical basket concentric with a tubular wand, the combination therewith of a filter paper cup having a flat annular bottom coextensive with and lying flat on the bottom of said basket and having an integral upstanding steam and heat-set sidewall only at the outer periphery of said annular bottom, said upstanding sidewall being fluted with accordian pleat-type flutes and said flutes being under compression by the fact that said upstanding sidewall normally flares outwardly when unconfined by said basket, but is constrained to a vertical position by said basket, in which the filter paper is composed essentially of bleached cellulose fiber from chemically processed wood pulp, is uncalendered, is unsized, is creped from about 6 to about 15 percent, and has a basis weight between about 28 and about 40 pounds, in which the sidewalls of the filter cup have at least 1 flute every 15°

, and in which said flutes are steam and heat set by heating the cups to a temperature of about 400°

to 420°

F to a moisture content between about 3 and about 6 percent while the sidewall is constrained in a cylindrical position, and substantially only the outermost apices of said flutes are substantially entirely in contiguous relationship with the inner wall of said basket into which said paper filter cup is placed.

2. The percolator of claim 1, in which the sidewalls of the filter cup have at least 1 flute every 10°

.

3. The percolator of claim 1, in which the basket has an axially disposed, tubular collar which projects upwardly from the bottom of said basket and embraces said wand with a sliding fit whereby the basket can be removed from said wand and in which the annular bottom of said filter cup extends from said upstanding sidewall to and terminates in contact with said collar.

4. The percolator of claim 3, in which the sidewalls of the filter cup have at least one flute every 10°

.

5. A filter paper cup adapted for use in a percolator having a cylinderical basket concentric with a tubular wand comprising an annular bottom having an integral upstanding steam and heat-set wall only at the outer periphery of said annular bottom, said upstanding wall flaring outwardly and being fluted with accordian pleat-type flutes, and in which the filter paper is composed essentially of bleached cellulose fiber from chemically processed wood pulp, is uncalendered, is unsized, is creped from about 6 to about 15 percent, and has a basis weight between about 28 and about 40 pounds, in which there is at least one flute for every 15°

, and in which said flutes are steam and heat set by heating the cup to a temperature of about 400°

to 420°

F, steaming with moist steam of about 90 percent quality, and then dried at a temperature of about 400°

to 420°

F to a moisture content between about 3 and about 6 percent while the sidewall is constrained in a cylindrical position, the outermost apices of said flutes being rectilinear so that, when the filter cup is inserted into the cylindrical basket of said percolator with the annular bottom of said filter cup being coextensive with and resting on the bottom of said basket and extending from said tubular wand to the outer wall of said cylindrical basket, substantially only the outermost apices of said flutes will be in substantially entirely contiguous relationship with said inner wall.

6. The filter paper cup of claim 5, in which there is at least one flute for every 10°

.