Importance

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Abstract

An apparatus (1) for the shaping of plastics material pre-forms (10) into plastics material containers (20), with a movable carrier (2) on which are arranged a plurality of shaping stations (40), wherein these shaping stations (40) form in each case cavities in which the plastics material pre-forms (10) are capable of being expanded into the plastics material containers with a flowable medium, and wherein the shaping stations (40) have in each case stressing devices (42) which act upon the plastics material pre-forms (10) with the flowable medium, as well as stretch rods (8) which are capable of being introduced into an internal space of the plastics material pre-forms (10) in order to stretch the aforesaid plastics material pre-forms (10) in the longitudinal direction (L) thereof, and wherein the apparatus has at least one drive arrangement (30) in order to move the stressing devices (42) relative to the plastics material pre-form (10). According to the invention the drive arrangement (30) has at least one first valve device (34), wherein a change in a switching state of this valve device (34) triggers the removal movement of the stressing device (42) and the shaping station (40) has a safety means (36, 54, 56, 46) which even in the event of failure of an element of the first drive arrangement (30) effects or releases the removal of the stressing devices (42) from the plastics material pre-form in a manner dependent upon a pressure prevailing in the container at a pre-determined moment in time, in that a change in the switching state of the valve device (34) is constrained and/or avoided.

First Claim