Device for heating the internal surface of the open end of plastic tublar containers
AssigneeVittorio Tonazzi & C.S.r.l.
InventorGuido Bruno Tonazzi
Life of this patent
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Abstract
Device for heating the internal surface of the open end of plastic tubular containers, consisting of a heating head (1) which has a cross-section corresponding to the shape of the tubular container and can be coaxially inserted so as to make contact, inside the open end of the tubular container (3) itself, along a section corresponding to the section (3a) to be softened internally, a heating head (1) being provided internally with electrical heating resistances (2), there also being provided a device (3) for pressing the tube against the heating head (1) during heating so that the heat is transmitted to the internal surface of the container of direct-contact conduction.
Claims10
Device for heating an internal surface of an open end of a plastic tubular container, comprising a heating head which has a cross-section corresponding to a shape of the tubular container and can be coaxially inserted inside the open end of the tubular container so as to contact the internal surface of the tubular container along a section of the tubular container to be softened internally, said heating head being provided internally with heating means;
- and means for pressing said section of the tubular container against the heating head, which is inserted inside the open end of the tubular container, during heating so that heat is transmitted from the heating head to the internal surface of the tubular container by means of direct-contact heat conduction, said pressing means releasing pressing engagement with the section of the tubular container to allow withdrawal of the heating head therefrom upon completion of the heating.
A device for heating an internal surface of an open end of a plastic tubular container, comprising a heating head which has a cross-section corresponding to a shape of the tubular container and can be coaxially inserted inside the open end of the tubular container so as to contact the internal surface of the tubular container along a section of the tubular container to be softened internally, said heating head being provided internally with electric heating resistance;
- and means for pressing said section of the tubular container against the heating head during heating so that heat is transmitted from the heating head to the internal surface of the tubular container by means of direct-contact heat conduction, wherein said pressing means includes a rigid annular body kept fixed coaxially to the end of the container undergoing heating and provided with ducts respectively for supplying and discharging a fluid supplied under pressure, said ducts emerging in an annular seat accommodating a sheath made of elastically yielding material shaped so as to be able to be held against the annular body by counter-plates integral with the body itself so that the introduction of a fluid under pressure into the annular seat causes radial expansion of the sheath in the direction of the longitudinal axis of the tube which is thus compressed around the heating head.
Dependencies are inferred from the claim text.