1. Field of the Invention
The invention relates to a method and an apparatus for the separation of tubes which are produced continuously on a row of cylindrical mandrels, continuously coupled to one another, by the mandrels being advanced in a conveying direction.
2. Background Description
An automated method of producing multilayer tubes has been disclosed by DE 27 50 642 C2, in which rubber and reinforcement layers are wound onto a rotating mandrel mounted in a fixed position. In this case, a material feed unit is moved in the longitudinal direction along the mandrel. A disadvantage of this method is that this production method does not work continuously, but is limited to the length of the mandrel. In addition, the thickness and the angle of the wound-on rubber and reinforcement layers can not be applied with sufficient accuracy.
DE 44 23 602 A1 discloses a similar winding method in which the tube is not cut until after its vulcanization in order to reduce entrapped air between the rubber and reinforcement layers. In addition, the fabric ends are fused after being cut open, so that an adverse penetration of air between the rubber and reinforcement layers is prevented.
A winding method for the continuous production of tubes is described in DE 1 180 513, in which rubber and reinforcement layers are wound onto a row of mandrels lined up endlessly one behind the other and advanced in a conveying direction. The tube is vulcanized onto the mandrels. The mandrel sections are then drawn off and releasably attached to the end of the mandrel section running into the winding machine. In a disadvantageous manner, the precision required for air spring bellows cannot be ensured during the winding method. In addition, the mandrels are thermally loaded during the vulcanization and there is the risk of the mandrels being deformed, so that a uniform quality of the tubes can no longer be ensured.
An apparatus for producing curved rubber tubes is described in DE 25 45 058 C3, in which apparatus, by means of at least one extruder and a yarn reinforcing machine, rubber and reinforcement layers are applied to mandrels advanced continuously in the conveying direction. In this case, the mandrels abut against one another directly in a seamless manner. In a cutting device, two mandrels are in each case mutually displaced in such a way that a gap in which a cutting blade of the cutting device can engage is produced between their end faces. In a disadvantageous manner, the yarn braiding in this case is stretched in the tube and changed in its position. The mandrels are flexible and are brought together with the tube piece located on a mandrel into a curved position and are vulcanised in a vulcanisation unit. The vulcanised tube is then separated from the mandrel.