Abstract: An article-handling machine for carrying out an operation on an article is disclosed. The article-handling machine includes a carousel configured to convey the article along a path. The carousel includes one of at least one seat or at least one pin. The article-handling machine further includes a modular operative group configured to carry out the operation on the article. The modular operative group includes the other one of at least one seat or at least one pin. The at least one pin is configured to engage the at least one seat, so as to dock the modular operative group to the carousel. The article-handling machine further includes at least one constraining assembly for constraining the at least one pin inside the at least one seat. The constraining assembly is configured to move towards and away from the at least one seat between a rest configuration and an operative configuration.