Machine for the working of tubes provided with an optical sensor for measuring the forward displacement of the tube being worked and/or the rotational displacement of the same about the longitudinal axis thereof

A machine for the working of tubes (T), comprising:

• a working head carrying working tools suitable for carrying out one or more working operations on the tube (T),
• a tube feeding unit for feeding the tube (T) along an longitudinal axis (x) thereof towards the working head,
• a programmable control unit arranged to control the tube feeding unit and the working head, and
• an optical sensor arranged downstream of the tube feeding unit to optically measure, while the tube (T) is being worked, a forward displacement of the tube (T) along said longitudinal axis (x) and/or a rotational displacement of the tube (T) about said longitudinal axis (x), wherein the optical sensor comprises a light source for illuminating a surface portion (S) of the tube (T), a camera for acquiring images of said surface portion (S) of the tube (T), and a digital processing unit for determining at each time instant, based on a comparison of the image of said surface portion (S) of the tube (T) acquired by the camera in that time instant with an image acquired at a preceding time instant, the forward displacement of the tube (T) along said longitudinal axis (x) and/or the rotational displacement of the tube (T) about said longitudinal axis (x).