Rotary stretch blow moulding machine comprising a magnetically controlled stretch rod
AssigneeSidel
InventorAlain Evrard
Life of this patent
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Abstract
A machine for making thermoplastic containers by stretching and blowing a preform, comprising several molding stations mounted on a rotary carrousel, each station being provided with at least a stretch rod whereof the sliding movement is controlled along an axis (An). The stretch rod is controlled by a magnetic device having at least a fixed magnetic guide arranged about the axis of the carrousel and a slide which is integral with the stretch rod and bears at least a magnetic shoe and the shoe and the guide co-operate by magnetic coupling such that the guide imposes a predetermined axial movement on the slide.
Claims8
Machine for manufacturing containers made of thermoplastic material by drawing and blow-molding a preform (10), of the type having several blow-molding stations (12) that are mounted on a carrousel (14) driven in continuous rotation around its axis (A1) with respect to a frame (46) of the machine, and of the type in which each station (12) is equipped with at least one drawing rod (20) that is slidably controlled along its axis (An) in order to draw the preform (10) during the blow-molding operation, characterized in that the drawing rod (20) is controlled by a magnetic device comprising at least one fixed magnetic guide (36, 38, 40, 42) placed around the axis of rotation (A&) of the carrousel (14) and a slide (24) that is integral with the drawing rod (20) and which carries at least one magnetic block (32, 34), and in that the block and the guide cooperate by magnetic coupling so that, depending on the angular position of the carrousel (14), the guide imposes a specific axial displacement on the slide (24).
Dependencies are inferred from the claim text.