Covering apparatus, which comprises: - a support structure provided with a framework, which comprises at least two lateral crosspieces that are parallel to and side-by-side each other, each of which longitudinally is extended along a corresponding first extension direction; - a series of covering blades placed one after the other according to said first extension direction, each of said covering blades being extended, according to a longitudinal axis thereof substantially orthogonal to said first extension direction, between two opposite ends supported by the respective said lateral crosspieces; - movement means mechanically connected to said covering blades and arranged for rotating each of said covering blades around a corresponding rotation axis, parallel to said longitudinal axis, between a closed position and at least one open position; said movement means comprising a movement bar, which is longitudinally extended along a main direction substantially parallel to said first extension direction and is extended, transverse to said main direction, between an upper longitudinal edge and a lower longitudinal edge; said movement bar being movable at least along a plane orthogonal to said rotation axis of said covering blades in order to move said covering blades between said closed position and said open position; each said covering blade comprising a first pin at least rotatably constrained to said movement bar, and a second pin at least rotatably constrained to the corresponding said lateral crosspiece; wherein said movement bar is provided with multiple first housing seats, each of which is extended from a first passage opening, which is made on either said upper longitudinal edge or said lower longitudinal edge, and a first abutment portion, which engagingly receives said first pin; said covering apparatus being characterized in that it comprises multiple first retention elements, each of which is inserted in the corresponding said first housing seat, is engaged with said movement bar and is provided at least with a first blocking portion interposed between said first pin and said first passage opening in order to retain said first pin within said first housing seat. - a support structure provided with a framework, which comprises at least two lateral crosspieces that are parallel to and side-by-side each other, each of which longitudinally is extended along a corresponding first extension direction; - a series of covering blades placed one after the other according to said first extension direction, each of said covering blades being extended, according to a longitudinal axis thereof substantially orthogonal to said first extension direction, between two opposite ends supported by the respective said lateral crosspieces; - movement means mechanically connected to said covering blades and arranged for rotating each of said covering blades around a corresponding rotation axis, parallel to said longitudinal axis, between a closed position and at least one open position; said movement means comprising a movement bar, which is longitudinally extended along a main direction substantially parallel to said first extension direction and is extended, transverse to said main direction, between an upper longitudinal edge and a lower longitudinal edge; said movement bar being movable at least along a plane orthogonal to said rotation axis of said covering blades in order to move said covering blades between said closed position and said open position; each said covering blade comprising a first pin at least rotatably constrained to said movement bar, and a second pin at least rotatably constrained to the corresponding said lateral crosspiece; wherein said movement bar is provided with multiple first housing seats, each of which is extended from a first passage opening, which is made on either said upper longitudinal edge or said lower longitudinal edge, and a first abutment portion, which engagingly receives said first pin; said covering apparatus being characterized in that it comprises multiple first retention elements, each of which is inserted in the corresponding said first housing seat, is engaged with said movement bar and is provided at least with a first blocking portion interposed between said first pin and said first passage opening in order to retain said first pin within said first housing seat.