Shedding mechanism and jacquard-type weaving loom equipped with such a mechanism

This shedding mechanism includes a housing and a movable hook which can be retained by a selection device including at least one electromagnet immobilized in the housing and which includes a ferromagnetic core comprising first and second pole faces (S, S). The electromagnet also includes a non-magnetic portion and a retaining lever configured to retain the movable hook. The retaining lever is pivotally mounted about an oscillation axis (A) and includes a ferromagnetic armature that interacts magnetically with the first and second pole faces. The non-magnetic portion of the electromagnet includes a surface (S) for guiding the pivoting of the retaining lever. This guide surface cooperates with the retaining lever in a direction radial to the oscillation axis (A) between a remote position and a contact position. The guide surface (S) is cylindrical with a circular base, centered on the oscillation axis.