Key having a retractable insert and corresponding deployment module

A deployment module for an insert for a key having a retractable insert designed to be mounted in a casing of said key, the module comprising:

• the insert mounted in a pivotable manner about a pivot axis and comprising a key-bit support and a key bit secured to said support;
• an insert deployment mechanism mounted in said casing and comprising:
• a push button housed axially in an associated housing of an upper half-shell of the casing and protruding from this upper half-shell in order to be actuated by a user, and
• an elastic return element comprising:
• a first end that is connected to the insert at the support via two parallel lips at the bottom of the push button, for urging said insert into a pivoting movement toward a use position when the push button is actuated, and a second end positioned between two holding pegs for support which define, on either side of the pivot axis, a space for angular travel of the second end of the elastic return element at an angle of between 10° and 90°,
• wherein the space for annular travel between the two holding pegs holding the second end of the elastic return element is larger than a space between the two parallel lips in the push button which house the first end of the elastic return element, so as to facilitate the insertion of the second end into the space between the two holding pegs after insertion of the first end into the parallel lips.