Electric lock with multiple-function spring

An electric lock with multiple-function spring, comprising:

• a locking element that is engageable in a respective selvage of a jamb;
• a body;
• a decoding assembly adapted to accommodate a component that bears a code;
• a first actuation element, connectable to an internal handle and directly associated with said locking element;
• an electromechanical device;
• a second actuation element, connectable to an external handle, and coupled to said locking element by way of said electromechanical device;
• wherein said second actuation element comprises a protruding stem that is rigidly coupleable to the external handle;
• a rotating plate;
• a contrast, rotatable, plate;
• and a rotatable sleeve, said rotating and contrast plates resting freely on said sleeve, which is rigidly coupled to said locking element, said plate, said contrast plate and said sleeve being provided with respective notches;
• and wherein said electromechanical device is constituted by an electric motor that has a shaft, a worm screw fitted on said shaft, a spring with opposite end arms and a central portion, and a slider which is coupled to said worm screw by way of said spring in which a first one of the end arms is fixed on the body of the lock, the central portion is engaged on said slider, and a second one of said end arms is accommodated between two successive crests of said worm screw, said slider having a head and being provided, on said head, with a coupling means that is adapted to enter said notches when the slider is arranged in a forward position for rigidly coupling to each other said plate, said contrast plate and said sleeve.