Apparatus for producing containers of thermoplastic material

Claim 1

Apparatus for blow moulding hollow plastic bodies comprising: a plurality of pairs of mutually joinable half-moulds capable of being opened and closed, linked to an appropriate rotary apparatus carrying said half-moulds, support devices for carrying preforms corresponding to said half-moulds, a preform feeding mechanism adapted to supply an orderly sequence of preforms held at an appropriate blow-moulding temperature into the respective pairs of half-moulds associated to said rotary apparatus, which are to this purpose kept in their opened position, a retrieval device adapted to remove the finished container from the respective pair of half-moulds after the opening thereof, an opening and closing mechanism adapted to close the half-moulds after the passage thereof through the position of the preform feeding mechanism, and to open them before the passage thereof through the position of the finished-container removal mechanism, characterized in that said pairs of half-moulds are constituted by a fixed half-mould and a moving half-mould that is capable of being opened from and closed against said fixed half-mould, said fixed half-moulds being arranged in a substantially vertical position, and the respective moving half-mould being adapted to be closed by accomplishing a substantially rotary movement about a horizontal axis of rotation, characterized in that said opening and closing mechanism of any of said moving half-moulds comprises: a first class lever and a third class lever, a structure firmly associated to said fixed half-moulds, a connecting member that joins the point of resistance of said first class lever with the point of power of said third class lever, said resistance and power points being pivotally connected to the extreme ends of said connecting member, an actuating member provided with two extreme ends, of which the first extreme end is connected to the power point of said first class lever, the fulcra of said first class lever and said third class lever being pivotally applied on respective distinct points of said structure firmly associated to said fixed half-moulds, and said moving half mould being applied on the arm of said third class lever which is opposite to the related fulcrum with respect to the corresponding power point.