Abstract: A reciprocating internal combustion engine (10) which comprises a tank (23), at least one cylinder (11), a piston (12) that can perform an axial reciprocating movement housed within this cylinder, this piston including a head and an arm hinged to this head, and at least one intake valve (19) and one exhaust valve (20) provided on the cylinder above said piston (12) and above two injectors (21a and 21b). The engine (10) is equipped with a device (27) for producing, by electrolysis of water, gaseous dihydrogen that is fed in the cylinder (11) and an explosion starts moving the piston (12) beyond a top dead center (TDC). A predetermined volume of water is then injected and instantaneously vaporized by the heat produced by the explosion of the gaseous dihydrogen. The hot steam pushes the piston (12) towards the bottom dead center (BDC) where the steam is then discharged through the exhaust valve (20). This engine only produces steam and thus is clean.

Abstract: A method and apparatus is provided for selectively cutting sheets of paper of variable length from a paper supply having a continuous web moving from an upstream location to a downstream location through a pair of pinch rollers and along a predetermined path to a rotary cutter. A controller controls the rotation of the rotary cutter. First and second sensors sense the angular positions of the rotary cutter and pinch rollers, respectively, to provide respective input signals to the controller indicative thereof. A format selector, controlled by an operator, provides a third input signal to the controller indicative of the speed and format for cutting individual sheets from the web. The controller is responsive to the first, second and third signals so that the rotary cutter cuts the sheets to the desired length and the pinch rollers feed the web at a desired speed.