Link 1, designed as a push button, slides in fixed guides b and is held in its upper position by spring 4. Link 2 is connected by turning pair B to link 1 and has, at its end, pin a which slides along fixed slot p. Link 3, turning about fixed axis A, is connected by spring 5 to link 2. When button 1 is pressed, pin a of link 2 slides along slot p and shifts link 3 from one extreme position to the other. After the button is pressed for the first time link 2 is in the position shown by the dash lines. Link 3 is shifted back to its initial position by pressing the button again.
$355$SL,SE$