Abstract: A brewing device (2) for an espresso-type coffee machine including a brewing chamber (12) for receiving ground coffee, a movably mounted pressure piston (13) in translation with a stroke that extends from an upper retracted position in which the pressure piston (13) is located above the brewing chamber (12) to a lower tamping position in which the pressure piston (13) enters said brewing chamber (12) and a potentiometer controlled by driving means during the stroke of the pressure piston (13) to measure the tamping position of said pressure piston and to thereby calculate the height of the compressed cake of ground coffee. The driving means only act on the potentiometer for a portion of the stroke of the pressure piston (13).

Abstract: A brewing device (2) for an espresso-type coffee machine including a brewing chamber (12) for receiving ground coffee, a movably mounted pressure piston (13) in translation with a stroke that extends from an upper retracted position in which the pressure piston (13) is located above the brewing chamber (12) to a lower tamping position in which the pressure piston (13) enters said brewing chamber (12) and a potentiometer controlled by driving means during the stroke of the pressure piston (13) to measure the tamping position of said pressure piston and to thereby calculate the height of the compressed cake of ground coffee. The driving means only act on the potentiometer for a portion of the stroke of the pressure piston (13).

Abstract: A heat exchanger for cooling motor vehicle exhaust gases, which heat exchanger is to be fitted into an exhaust line of the vehicle and having at least three tubes in contact by way of their outer walls with cooling air, in which the exhaust gases are brought to circulate.

Abstract: The invention concerns a cooling device comprising, inside a substantially cylindrical outer casing (2) having a side wall traversed by orifices (3) a first flow path consisting of a tube (16) extending in an axial direction of the cylindrical casing and a second flow path (17) consisting of a plurality of tubes (17a, 17b, 17c) fixed by maintaining means (14a, 14b, 14c, 14d) in substantially parallel arrangements in an axial direction of the cylindrical casing (2), a duct (4) for the intake of exhaust gases, a duct (6) for evacuating exhaust gases and means for dispensing (15a, 15b, 15c, 15d) exhaust gases arranged inside the cylindrical casing (2) to cause the exhaust gases to pass through the first and through the second flow paths. Switching means consisting of a valve controlled (11) for opening and closing one or the other at least of the flow paths (16, 17) enable to cause the gases to pass inside the first flow path (16) with little heat loss or inside the second flow path (1) with high heat loss.