The invention proposes a switch (10) comprising a casing (12) which carries a pair of fixed contact elements (48), a contact bar (96) which is movable between a rear closure position and a front opening position, and a member (60) for actuation of the movable contact bar (96) which is mounted so as to slide between a rear rest position and a front triggering position, the movable contact bar (96) and the actuation member (60) constituting a movable assembly, and the switch (10) comprising a return spring (108) which co-operates with the movable contact bar (96) so as to urge it towards its rear closure position. |