Hermann Berstorff Maschinenbau Gmbh

Hermann Voss

Manfred Mank

An apparatus is provided for the conveyance of preforms through a heating station to a stretching and blowing machine during the production of hollow articles from thermoplastic plastics materials, means of which preforms having different neck diameters can be heated satisfactorily and extremely uniformly without major modification of the apparatus. This is achieved by providing two endless toothed sections extending parallel to each other and have preform pick-up means mounted thereon. The preforms are collected and retained in position by the pick-up means as they pass through the heating station. The mutual spacing of the belts and, hence, of the pick-up means from one another and from the heating devices is adjustable. A further pair of endless drive belts are provided which rotate the preforms at desired circumferential speed about their own axes as they pass through the heating device so as to promote an even distribution of the heat in the preforms.

Apparatus for conveying preforms

A stretching and blow-molding apparatus for producing hollow bodies from thermoplastic plastics material comprises a rotatable blow wheel assembly on which a number of molds are mounted. Each mold comprises two mold halves mounted on a common pivot. The apparatus includes a locking device which has a frame-like configuration and comprises a continuous shaft which passes through a set of aligned bores formed in pawls provided on the external surface of one mold half and a locking member which comprises a plurality of locking sections disposed in aligned bores formed in pawls provided on both mold halves, which pawls are interdigitated in the locked position. The uppermost and lowermost locking sections are connected to the continuous shaft. Vertical movement of the continuous shaft or of the locking section causing corresponding vertical movement of the other. The individual locking sections have a length corresponding to the length of the bore in each pawl and end-abut one another. By raising or lowering the frame by a few centimeters so to move each individual locking member from a position in which it is totally located in a single bore to a bridging position in which it is disposed in the bores formed in two adjacent, interdigitated pawls formed on different mold halves, locking over the entire length of the mold joint can be achieved.

Stretching and blow-molding apparatus incorporating a mold-locking device

An arrangement for opening and closing mold halves of a blow mold is disclosed. The blow mold generally forms part of a stretching and blowing machine for blow-molding hollow bodies from thermoplastic plastics materials. The mold halves are coupled to driven rocker arms, which are driven by driving rocker arms of a four-link gear, the pivot of the four-link gear being disposed immediately at the end of the common pivotal axis of the mold halves. The driving rocker arm of the four-link gear is formed by cylinders, which are provided with cam tracks on their external curved surfaces in which rollers mounted on a sliding cam controller travel.

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Seevetal, Germany

Hermann Voss