Espresso machine with an infusion piston displaceable in an infusion cylinder
US6711988B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 5, 2002 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | Apr 5, 2022 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47J31/36
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
An espresso machine is provided with an infusion piston displaceable inside an infusion cylinder. The infusion piston is force-connected to a spring and to a device for activating the infusion piston and, in a first position, tightly encloses ground coffee inside an infusion chamber of the infusion cylinder between itself and an outlet sieve. A pressurized water inlet is connected to the infusion chamber, the infusion piston is automatically pushed by the pressure of the infusion water flowing into the infusion cylinder and counter to a spring force to a second predetermined position, thereby expanding the infusion chamber, whereupon during a pressure drop inside the infusion chamber the infusion piston is returned automatically to the first position. The infusion piston can essentially be displaced proportional to a pressure increase inside the infusion chamber, caused by the infusion water flowing in, until it reaches a nominal opening pressure for a frothing valve that closes off the infusion chamber in a downstream direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.