The coffee preparation unit comprises a simplified injection group consisting of an assemblage of plastic elements attached to the lower plate (12) of its front portion (11). This group consists of a crosspiece (70) covered by an injection element (60) on an upper distribution chamber (63), which is traversed by a plurality of longitudinal channels commu¬nicating with a spray (51) which is attached to the front portion of the injection piece (60). The container holder (55) is attached directly to the lower plate (12) of the front portion (11). The coffee preparation unit also comprises an inpidual heater (46) for each coffee preparation post, with a flexible tube serving as a hydraulic inlet (47). The inven¬tion is of interest to manufacturers of professional “espresso” coffee machines.35860
20 Claims, 9 Drawing Sheets
OBJECTS OF THE INVENTION
INDIVIDUAL UNIT FOR PREPARING AND
SERVING COFFEE FOR “ESPRESSO” TYPE
COFFEEMAKER
REALM OF THE INVENTION
This invention relates to an inpidual unit for preparing and serving coffee for an “espresso” type coffeemaker, comprising an injection group with a simplified structure associated with an inpidual heating unit for the preparation station, making the preparation location functionally inde-pendent
BACKGROUND OF THE INVENTION
A complete, multi-unit coffeemaker for preparing uespresso?, type coffee is formed by juxtaposing a plurality of preparation units or posts.
Multi-unit coffeemakers, which are the subject of the invention, generally comprise a single heating unit common to the various coffee preparation posts and also for the production of hot water or steam for other purposes, which are delivered separately by a plunger.
The heated hot water passes indirectly through the com¬mon heating unit and supplies an inpidual preparation circuit, with an electrovalve control, followed by a coffee injection unit formed of a mechanical block through which the hot water passes and which supports the container holder.
The mechanical injection block has a central projection which extends downward. This projection forms the area for delivering the coffee into the cup, and also has a seal and a diffusion element called a spray attachment. The projection is formed in the central portion of the mechanical injection block and then machine-finished.
In addition to the expensive material forming the support and its mechanical complexity, which make the unit costly, this system has other disadvantages relating to maintaining the ideal temperature for coffee preparation:
Because of the inertia of the metal mass surrounding the interior canal through which the water passes before injection, regulation is difficult during intense usage, that is, continuous, high-speed use. After a certain amount of coffee has been prepared, the coffee becomes burning hot.
Conversely, when coffee is prepared at the beginning of a heating cycle, the unit is slow to reach the optimal coffee preparation conditions that prevail during steady usage.
Some manufacturers have solved this problem by adding thermal insulation to the massive connecting pieces between the heating unit and each injection group, or by making these pieces hollow so the water circulating from the heating unit circulates through them.
Unfortunately, both of these modifications have added only slight improvement.
In practice, the hot water transmits calories to the pieces connecting the heating unit and the injection group which, having been heated to a certain temperature by an even greater flow of water, remain at a temperature close to the water temperature as they are continuously heated by the frequent passage of the water. Thus, the water becomes too hot when it exits, since its temperature leaving the heating unit is regulated on the basis of intermittent use, taking into account loss of calories as it passes from the heating unit to the corresponding injection group.
Thus, this hot water transfer system does not ensure the production of high quality coffee under varying conditions. 咖啡机英文文献和中文翻译:http://www.751com.cn/fanyi/lunwen_34033.html