The present invention relates to an improved machine for manufacturing vulcanized-rubber tubes.
A machine disclosed in EP no. 0410367 in the name of the same Assignee is currently used to manufacture vulcanized-rubber tubes.
Said machine comprises a pair of heads arranged oppositely with respect to mandrels which rotate two tubular cores supported by supporting elements with fixed rollers on a supporting frame.
The tubular cores are flanked by a thermally insulated openable box-like container suitable to contain said cores when they are surrounded by the tubes to be vulcanized and after the unloading thereof, which is performed with transfer means.
The heads of the container are provided with terminal strips for supplying electrical power to the cores and for heating them by means of the Joule effect.
Means for removing the cores from the container are provided.
Wrapping of the cores with spirals of the materials to be used to manufacture the tubes is performed with the aid of a carriage which can slide along rails arranged on the ground parallel to said cores.
An operator is carried on board the carriage from one end of the machine to the other and holds the various coils of material to be wrapped in his hands.
Naturally, the operator is capable of performing a single wrapping operation at a time on a single core at a time.
This constitutes a considerable operational limitation for the machine as regards its production rate, which is consequently limited.
It should also be noted that in order to achieve qualitatively good production of the tubes, the various spirals obtained from the ribbons being wrapped must mutually overlap in a preset and constant manner.
The presence of an operator, onboard the carriage, who distributes the materials, introduces in the evaluation of qualitative results the variable constituted by the skill of said operator in keeping the reels from which the materials are unwound during carriage movement in the correct position with respect to the machine.