of the spring means 16 the object 2 a is repositioned without any difficulty on the longitudinal conveying path during the blockage of the flow of objects 2 it is possible to insert a cleat 39 on the feed trajectory of the objects 2 on the conveyor belt 3 at the exit of the passage 5 said cleat 39 being inserted downstream from the most downstream object 2 a of the objects 2 blocked by the flaps 10 11 in the passage 5 given that the conveyed objects 2 are preferentially parallelepiped it is indeed necessary to provide gaps in the continuous flow of objects 2 to enable the insertion of such a cleat 39 and consequently enable the formation of batches of objects each batch consisting of the number of objects 2 positioned between two cleats 39 which are inserted successively in the flow of objects 2 at the exit of the passage 5 the cleats 39 are spaced by a pitch p which is substantially greater than the length l of the batch of objects of the order of a few millimeters between 1 and 5 mm depending on the nature of the objects in order to enable the release of the objects 2 blocked between the two flaps 10 11 the pivoted flap 10 then returns to the initial position thereof i e in a position substantially parallel with the feed direction of the conveyor belt 3 if two flaps 10 11 are provided pivoting the spring means 16 facilitate the return of said flaps 10 11 to the position thereof.