Moulding device for producing thermoplastic containers

A molding device for producing containers by blow molding or stretch blow molding from preforms made of a heated thermoplastic, said device comprising at least one mold comprising at least two half-molds, mutually displaceable between an open position in which they are separated from one another and a closed position in which they are tightly pressed against one another by respective cooperating bearing faces, defining a joint plane, the two half-molds having at least two respective corresponding edges of their respective bearing faces which are radially designed in the form of two mutually overlapping edges with respective opposing mating faces in the closed position of the mold, locking means being functionally associated with said overlapping edges, that wherein said locking means (14) are designed in the following manner:

• one of said overlapping edges located on the inside has a mating face (internal mating face) which terminates in a hook and which has a recess adjacent to the hook;
• the other of said overlapping edges located on the outside has a mating face (external mating face) which terminates in a hook and which has a recess adjacent to the hook;
• said respective hooks and recesses of said internal and external overlapping edges extend substantially over the entire height of the mold;
• a gib extending substantially over the entire height of the mold is mounted rotatably about a pin corresponding to one of its edges in one of said recesses and in contact with the respective hook;
• and
• drive means are functionally associated with said gib for pivoting about its pin between two extreme positions,
• whereby the gib may occupy two functional positions, namely:
• a position inserted into its mounting recess in which the gib does not engage the opposing recess of the other overlapping edge and allows a mutual relative displacement of the two half-molds (opening and closing of the mold);
• and
• a projecting position in which the gib is pivoted toward the outside of its mounting recess and—the two half-molds being in the closed position—engages in the opposing recess of the other overlapping edge such that, when the two half-molds are subjected to forces separating them from one another (pre-blow molding, blow molding), said gib is engaged with the two respective hooks of the two overlapping edges and mechanically holds the two half-molds.