Process for making filter cups
US4235160A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1978 |
| Grant date | Nov 25, 1980 |
| Priority date | — |
| Expiry date | Jun 21, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T83/395
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
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. The filter cups are formed by cutting and forming them into a nest of cups having an imperforate bottom, 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.