Patent ID: 9623519
Date: 2017-04-18
CPC Classifications: A47J,B01D,B23P,Y10T

Claim:
1. A method of fabricating a coffee filter, comprising: forming a plurality of tapered exit regions in a substantially flat first portion of a metallic member, the substantially flat first portion including first and second opposed major surfaces, the plurality of tapered exit regions extending from the second major surface of the substantially flat first portion to respective vertices interior to the substantially flat first portion; providing a hole uniformity enhancement region extending between the first major surface of the substantially flat first portion and the vertices of the plurality of exit regions; forming respective holes that extend from the vertices of the plurality of tapered exit regions through the hole uniformity enhancement region to the first major surface of the substantially flat first portion; and micro-machining the first major surface of the substantially flat first portion to remove a part of the hole uniformity enhancement region to a predetermined depth into the hole uniformity enhancement region, thus forming a micro-machined first major surface, wherein the predetermined depth is selected to prevent the micro-machined first major surface from meeting the tapered exit regions to maintain uniformity of the holes.