LU85315A1 - "EXPRESS" COFFEE MACHINE WITH A WATER PRESSURE INDICATOR - Google Patents

Description

"Express" coffee machine fitted with a 3'-pressure indicator device ".

The present invention relates to an "express" coffee machine.

It is known that in "express" coffee machines, it is necessary to have an indication of the pressure of the hot water which is pumped towards the brewing groups.

In fact, on this pressure depends the speed of the brew, and therefore the quality of the coffee produced. It is therefore necessary to exercise control of the water pressure in order to be able to intervene immediately and correct it, by acting on appropriate adjustment members, as soon as this pressure varies for any accidental reason.

Until now, as is known, normal diaphragm manometers have always been used to meet this requirement. But it is well known that such manometers have limits with regard to accuracy and reliability. . In particular, with regard to precision, the high general quality level obtained in current machines makes the use of membrane pressure gauges less and less acceptable.

Consequently, the present invention aims to create an "express" coffee machine provided with an indica- device. high precision and reliability in water pressure.

To this end, the invention relates to a machine of the above type characterized in that it comprises in combination; - a boiler for the production of hot water, - at least one coffee-distributor group, known per se, - at least one pipe fitted with a pump, for sending water to the distributor group, - a pressure transducer, electrical type, mounted in bypass on the pipe, downstream of the pump, 35 - a display member, known in itself, electrically connected to the transducer.

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Since an "express" coffee machine according to the invention uses an electrical type transducer, it has a reliability and, above all, an accuracy much greater than that of machines using membrane manometers.

We will now describe the invention in more detail with reference to the accompanying drawings, in which: - £ ig.1 is a schematic perspective view of an "express" coffee machine, according to the invention, in addition -10 as long as this machine is transparent; Fig.2 is a sectional view of a pressure transducer fitted to the machine of Fig.1.

An “express” coffee machine according to the invention, generally designated by 1 in FIG. 1, comprises a. 15 box-like covering structure 2 in which a boiler 3 is mounted.

The water flows through a pipe 4 provided with heat exchangers 5 in the sections passing through the boiler. Upstream of the heat exchangers 5, the pipe 4 is further provided with a pump 6 intended to pump water in the direction of coffee distributor groups 7 arranged immediately downstream of the heat exchangers 5.

A pressure transducer, generally designated by 8, is mounted in bypass on the line 4, downstream of the pump 6.

The transducer 8 comprises a threaded connection 10 to ensure its attachment to the pipe, a socket 11 fixed ^ ** on the connection 10 -and a cap, -of "closing 1J2_. _Le_ jraccord 10, and the socket Ί1 are drilled ^ internally — so as to form! 30 a cavity 13 open towards the pipe. In this cavity 13 is disposed a piezoelectric load cell 14 whose axis is substantially directed in the longitudinal direction of the cavity 13. The cell 14 has a hollow cylindrical rod 15 which engages with a tight fit in the fitting 10 35 and a head 16 on which the sleeve 11 exerts pressure. The head 16 therefore rests on the connector 10 with the interposition of a washer 17 and a seal 18.

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The electrical terminals 19 of the cell 14 are connected to a connector 20 disposed inside the cap 12. The cavity 13 is closed towards the pipe by a piston 21 guided to move in the cavity 13. Between the piston 21 5 and cell 14, a chamber 22 is thus formed which is completely filled with silicone grease. To prevent any leakage of grease towards line 4, the piston 21 is provided with a lip seal 23. The transducer 8 is then electrically connected, by conductors 24 starting from the connector 20, to a display member 25, known per se, arranged on the front part of the box-shaped covering structure 2.

The operating mode of the "express" coffee machine according to the invention is evident from the foregoing description.

When the pump 6 is in operation to see the hot water from it to the coffee distributor groups 7, the pressure of the water in the line 4 acts on the piston 21 of the transducer 8. The pressure is thus transmitted to the grease silicones in the chamber 22 and, from the latter, to the piezoelectric load cell 14. This provides an electrical signal proportional to the pressure. This signal is transmitted to the display member 25 via the connector 20 and the conductors 24.

It should be noted that the lip seal 23 25 prevents 2a silicone grease from coming into contact with water and at the same time gives the piston 21 the possibility of making small movements sufficient to transmit the ** pressure of water to the greased. '

Consequently, an "express" coffee machine according to the invention makes it possible to obtain an extremely precise and reliable measurement of the water pressure. The goal is therefore completely achieved.

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Claims (2)

<χ * - 4 - 1 °) "Express" coffee machine (1) characterized in that it comprises in combination: - a boiler (3) for the production of hot water, 5. at least one group distributing coffee (7) known per se * - at least one line (4) f provided with a pump (5) for sending water to the dispensing group, - a pressure transducer (8), of the elec-10 type stick, mounted in derivation on the pipe downstream of the pump, - a display member (25), known per se, electrically connected to the transducer. 2 °) "Express" coffee machine according to claim 1, characterized in that the transducer (8) comprises: 15. a "container (10,11) provided with an open cavity (13) connected in derivation to the pipe (4), - a piezoelectric load cell (14) housed in the cavity (13), - a piston (21) guided to move in the ca-20 vity near its opening, - a chamber (22 ) formed between the piston (21) and the cell (14), this chamber being completely filled with silicone grease, -a lip seal (23) on the piston.