Cutting unit for thermoplastic pipes

A cutting unit for thermoplastic pipes comprising:

• a rotary ring rotatable about an axis of rotation and in which a pipe is progressively moved in a sliding fashion such that a longitudinal axis of the pipe coincides with said axis of rotation;
• at least one cutting arm mounted on the rotary ring and equipped with a cutting tool and having a relative portion integral with said rotary ring, said at least one cutting arm also being movable between a first operating position, wherein said cutting tool is engaged with said pipe for exerting a cutting action, and a first rest position, wherein said cutting tool is disengaged from said pipe;
• at least one distance measurement sensor located on said rotary ring and configured for acquiring, during a rotation of said rotary ring, a plurality of representative values representing a first radial distance between said at least one measurement sensor and an outer surface of said pipe, said first radial distance being measured on a measurement plane transversal to said axis of rotation;
• a processing and control unit operatively connected to said at least one distance measurement sensor and configured to receive said plurality of representative values measured and to calculate, based on said plurality of representative values measured, at least one peripheral profile parameter representing a peripheral profile of said pipe on said measurement plane;
• at least one contact arm including at least one contact element for the pipe and having a relative portion integral with said rotary ring, said at least one contact arm being also movable between a second operating position, wherein said at least one contact element is in contact with said pipe for exerting an action for supporting said pipe, and a second rest position, wherein said at least one contact element is away from the pipe, said at least one contact element being diametrically opposite said at least one cutting arm;
• a third sensor located on said at least one contact element and configured for acquiring, at different angular positions of said at least one contact element, a plurality of third representative values representing a third radial distance between said at least one contact element and said outer surface of the pipe, said third radial distance being measured on said measurement plane.

A method comprising the following steps:

• providing a cutting unit for thermoplastic pipes comprising:
• a rotary ring rotatable about an axis of rotation and in which a pipe is progressively moved in a sliding fashion such that a longitudinal axis of the pipe coincides with said axis of rotation;
• at least one cutting arm mounted on the rotary ring and equipped with a cutting tool and having a relative portion integral with said rotary ring, said at least one cutting arm also being movable between a first operating position, wherein said cutting tool is engaged with said pipe for exerting a cutting action, and a first rest position, wherein said cutting tool is disengaged from said pipe;
• at least one distance measurement sensor located on said rotary ring and configured for acquiring, during a rotation of said rotary ring, a plurality of representative values representing a first radial distance between said at least one measurement sensor and an outer surface of said pipe, said first radial distance being measured on a measurement plane transversal to said axis of rotation;
• a processing and control unit operatively connected to said at least one distance measurement sensor and configured to receive said plurality of representative values measured and to calculate, based on said plurality of representative values measured, at least one peripheral profile parameter representing a peripheral profile of said pipe on said measurement plane;
• a second sensor located on said cutting tool and configured for acquiring, at different angular positions of said at least one cutting tool, a plurality of second representative values representing a second radial distance between said cutting tool and said outer surface of the pipe, said second radial distance being measured on said measurement plane;
• rotating said rotary ring;
• measuring, using said at least one distance measurement sensor, for a plurality of angular positions adopted by the rotary ring rotating about the pipe, the plurality of representative values;
• processing, using said processing and control unit, said plurality of representative values for calculating, based on said plurality of representative values measured, said at least one peripheral profile parameter.