Heated hose for carrying molten thermoplastic material

Abstract

A hose for transferring heated liquid, such as molten thermoplastic material. The hose includes a conduit that has an inlet end adapted to couple with a source of heated liquid, such as a heated supply tank, and a discharge end adapted to couple with a liquid dispensing apparatus, such as an applicator gun. In one embodiment, the hose may be covered by a woven outer sheath of polyamide that protects the underlying hose against abrasion damage. In another embodiment, the hose may include a hose cuff mechanically coupled with the liquid dispensing apparatus to bolster resistance to axial tensile forces and bending forces applied to the hose.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 485,456 filed on Jul. 8, 2003, and the disclosure of which is hereby incorporated by reference herein.FIELD OF THE INVENTION [0002] This invention relates to heated hoses and, in particular, to heated hoses for carrying molten thermoplastic material. BACKGROUND OF THE INVENTION [0003] Various manufacturing processes involve the transfer of a pressurized heated liquid from a source, such as a melter tank, through heated lengths of flexible heated hose to a liquid dispensing device, such as an applicator gun or a dispenser. The liquid dispensing device dispenses heated liquid onto a target surface in the form of a continuous bead or ribbon or as intermittent beads, droplets or deposits. Among the heated liquids frequently dispensed in this manner are thermoplastic materials, such as hot melt adhesives, that may be liquid or solid at room temperature. Such thermopla...

AI Technical Summary

Benefits of technology

The invention is a heated liquid transfer apparatus that includes a hose with a thermal insulation layer and a heating element, and a securement device for attaching the hose to a liquid dispensing device. The securement prevents relative axial movement between the hose and the liquid dispensing device. The invention also includes a hose cuff that prevents premature failure of the outer protective sheath of the hose and reduces the likelihood of breakage or shortage of insulation or electrical wires. The hose can be retrofitted in existing assembly line manufacturing processes. The technical effects of the invention include improved durability and flexibility of the hose, as well as safer and more reliable transfer of heated liquid.

Problems solved by technology

In assembly line environments, these hoses may fail due to tears in the sheath resulting from chaffing, abrasion or wear resulting from intermittent contact with objects in the work environment.

In rough duty assembly lines, rapid failure of the protective sheath may necessitate frequent hose replacements, which are expensive and temporarily halt the manufacturing process.

However, the corrugations may rub and scrape against the workpiece receiving the heated liquid, which damages the workpiece.

Nonetheless, the weakest point of the flexible hose, which represents the point most susceptible to breakage of insulation or electrical wires, is at this interface between the hose cuff and the hose.

The tensile forces may cause the outer protective sheath of the hose to retract and pull back from underneath the hose cuff and fret, unravel, and / or fray.

Damage to the outer protective sheath may expose and / or place unexpected stresses and strains on the underlying electrical wires and potentially precipitate secondary failures, such as wire breakage and electrical shorts.

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