Abstract: A vacuum-type transport device, used in cardboard printing units, comprising: a support structure; a suction hood; a vacuum fan; a plurality of plates on the lower surface of the suction hood; a first and a second plurality of belt-type conveyor means, with a pressure cylinder between them, that protrude from windows obtained in the lower surface of the suction hood; and motoring means for the device. The pressure cylinder is located next to the printing cylinder and the sheets of material to be printed pass between these cylinders and are dragged away by the belt-type conveyor means.

Abstract: A thermophotovoltaic converter of the type comprising a concentrating optical system and a transducer for solar radiation provided with at least one lens and with at least one photovoltaic cell is described.The principal feature of this converter is that the aforementioned transducer comprises at least a radiator having an irradiating surface substantially facing the sensitive surface of the photovoltaic cell and a selective filter disposed between the photovoltaic cell and the aforementioned radiator.