The invention describes an apparatus for producing double-walled composite tubes which have an outer wall with wave peaks and wave valleys and a smooth inner wall. The apparatus (10) has two rows of shaping-jaw halves (12, 14) which, along a common shaping section, form a shaping tunnel (16) for producing the composite tube. At least one pair of the shaping-jaw halves (14) located opposite one ano...

This invention finds application in the machining of stones and the like, and relates to a method for forming surface markings particularly on slabs of hard material or the like, and to an apparatus for carrying out such method. The method comprises the steps of providing a plurality of tools (8) for forming surface markings that are aligned with predetermined center-to-center distances (i), trans...

The gantry crane for lifting loads, particularly containers in harbour areas or the like, comprises a first (2) and a second (3) supporting portals for a substantially horizontal extended superstructure (4) to which a load lifting unit is associated, the first portal (2) being associable to the superstructure (4) by interposing first movable blocking means (7) in a configuration spaced from the se...