Patent ID: 8287271

Claim:
A moulding unit for a plant for blow-moulding plastic containers ( 2 ) from respective parisons ( 3 ), the moulding unit being movable along a defined path (P) and comprising: two half-moulds ( 17 a , 17 b ), movable relative to each other between a position of opening and a position of closing at least one cavity ( 19 ) for blow-moulding a respective container ( 2 ); and a locking device ( 21 ) for locking the two half-moulds ( 17 a , 17 b ) in the closed position, the locking device ( 21 ) comprising a first fastening element ( 22 ) associated with the first half-mould ( 17 a ) and a second fastening element ( 28 ) mounted on the second half-mould ( 17 b ), the first fastening element ( 22 ) being movable between a position of locking and a position of unlocking the two half-moulds ( 17 a , 17 b ), wherein the locking device ( 21 ) comprises, in combination: first elastic actuating means ( 30 ) comprising at least one spring ( 30 ) interposed between the first half-mould ( 17 a ) and the first fastening element ( 22 ) in order to move the fastening elements ( 22 , 28 ) to the locked position and normally hold them in that position; means for moving the first fastening element ( 22 ) from the locked position to the unlocked position against the action of the spring ( 30 ) and comprising a rocker ( 25 ) kinematically connected to the first fastening element ( 22 ) in order to rotate it about a predetermined axis, and wherein the first fastening element ( 22 ) has a substantially cylindrical shape, limited by a flat face, the second fastening element ( 28 ) comprising a socket ( 29 ) designed to receive and hold the first fastening element ( 22 ).