Piston-cylinder-assembly for a coffee brewing apparatus and a method of its operation
US4797296A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1987 |
| Grant date | Jan 10, 1989 |
| Priority date | — |
| Expiry date | Feb 24, 2007 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47J31/3609
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
The invention provides a piston-cyclinder-assembly for a coffee brewing apparatus, the assembly comprising a cylindric cavity serving as a brewing chamber, a closing member mounted on the cylindric cavity at one end thereof, and a piston which can be displaced into and retracted from the brewing chamber at the other end. The piston is equipped with internal brewing water channels leading to the front face of the piston and connected to a brewing water connector. The closing member has plate-like shape and is fixed against movement in axial direction of the brewing chamber but is pivotally mounted near the cylindric cavity. To drive the piston into the cavity and to retract it, and to pivot the closing member, first and second stepping motors, respectively, are provided which are operatively connected to a control unit. Another embodiment is provided with a normal electric motor to drive the piston and with a pressure sensor. As soon as the piston exerts a preselected pressure on the coffee powder in the brewing chamber, the displacement of the piston is stopped.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.