| 主权项 |
1. Machine for producing and dispensing beverages comprising at least a pump for the circulation of a fluid, a dispensing group for a beverage, a central control unit and a proportional valve operatively connected to said central control unit, said proportional valve, comprising a main body provided with a first connection element to the hydraulic circuit of the machine, configured for entering a fluid into the proportional valve, and with a second connection element to said hydraulic circuit of the machine, configured for the ejection of the fluid from the proportional valve, inside of the main body there being provided at least an inlet duct for the fluid, operatively connected to the first connection element, and at least an outlet duct for the fluid, operatively connected both to said inlet duct and to the second connection element, inside of the main body, in an inner chamber forming the intersection point between the inlet duct and the outlet duct, there being further inserted an actuator piston, movable according to reciprocating motion, which is capable of selectively putting in communication said inlet duct with said outlet duct, said actuator piston being operatively connected to an actuation mechanism, the proportional valve wherein, the actuation mechanism comprises at least an elastic actuation member made of a shape-memory alloy, as well as an electric current generating device, operatively connected to the elastic actuation member in order to modify, in a progressive and modulable manner, the value of the elastic force applied on the actuator piston through a temperature variation caused by the passage of electric current inside said elastic actuation member. |
