咖啡机英文文献和中文翻译(5)
Holder 55 may be attached at three points by other screw-pin connections to the subsurface of lower plate 12 on the subsurface of front portion 11.
Three conduits penetrate the disc forming cross piece 70 from side to side: a first central conduit 73 for a means of attachment to lower plate 12 of the subsurface of front portion 11, a second excentric conduit 74 for injecting hot water, and a final conduit 75 which may be, but is not necessarily, diametrically opposed to the second tube for connection with hydropneumatic storage 64 (FIGS. 5 through 7).
These conduits communicate hydraulically with the annu¬lar distribution chamber 63 of the injection piece and then with the spray through distribution channels 62.
In order to furnish hot water at an ideal, constant tem-perature to the injection region of annular distribution cham-ber 63 and avoid the problems caused by thermal inertia of the metal masses of the circuits and the injection block, each inpidual heating unit supplying each coffee injection group has a small volume, for example one liter, and the flexible distribution tubes made of thermally insulated plastic extend as far as the point of injection into the coffee. Likewise, the elements which constitute the injection unit are made of thermally insulated plastic.
The use of such thermally insulated plastic tubes virtually eliminates any change between the temperature of the water leaving the heating unit and its temperature at the injection point.
It is easy to thermally stabilize these elements at the optimal brewing temperature using a heating means, for example a thin electric resistor (not shown), applied or affixed to lower plate 12 in the region where the injection group is attached.
More specifically, the inpidual heater, known as an instant heat unit, is small in size, being formed of a closed container 76 of reduced volume with a least one heating plunger 77, a regulating sensor 78 associated with the heating unit control, and a safety sensor 79 maintaining the temperature below the dangerous level. Electrovalve 48 has two valves, one of which is a return valve for evacuation through a discharge element 80.
The coffee machine described consists of several juxta-posed inpidual units, functionally independent, for the preparation of coffee. They can be used separately, without engaging the entire machine and wasting energy. One of the preparation units can also be inpidually regulated for specialized uses without affecting the other units.
Next, the hydropneumatic storage 64 and its function in the hot water distribution for coffee preparation will be examined.
It consists of a small capacity container 81, preferably metal, in the form of a closed, mini-carboy, tightly con¬nected to the distribution circuit at the level of the annular distribution chamber 63 on injection element 60.
The interior volume of this mini-carboy forming the hydropneumatic storage is free, but closed and watertight, so that it acts as a hydropneumatic shock absorber.
It works in two different ways. Under compression, it absorbs the pressure spurts coming from injection pump 24, since the sealed interior, filled with air, serves as a pneumatic cushion during momentary pressure increases at the begin¬ning of the coffee preparation cycle, which generally con¬sists of a short, initial readying phase, followed by continu- ous drip-brewing. Since these two phases are separated by a short udown?, time, the initial pause in pressure, as well as the subsequent pressure rise, are neutralized by hydropneu¬matic storage 64.
The hydropneumatic storage 64 also works as a detente, so if injection pump 24 stops and the capacity has been inflated by the pressure of brewing, this energy is restored to the circuit and forces the unused water, or a portion of it, toward the discharge through electrovalve control 48 to be evacuated through discharge outlet 80.
According to another original feature of the invention, each electro valve control 48 rests on one of the metal elements of the body of the machine, which is used as a heat dissipator. This dissipation prevents the body of the valve from overheating, and thereby contributes to maintaining the water at the ideal coffee preparation temperature.