Judgment of the Court (First Chamber) of 3 December 1992 in Joined Cases C-140, C-141, C-278 and C-279/91 (Reference for a preliminary ruling by the Pretura Circondariale di Bologna): Mauro Suffritti and Others v. Istituto Nazionale della Previdenza Sociale (INPS) (Protection of workers - Direct effect of a directive - Expiry of the time limit for implementation)