Abstract: The invention refers to a device to regulate the dosage of fuel, to be used in engine feeding systems by suction of the fuel. The device is to be set in the main conduit of air, overlays the diffuser (7) and involves a set of laminar elements (1) displayed in a radial way according to a common plan, being the fastening of its peripheral extremities achieved by means of its insertion in a double ring (2) which bears a central shutter through narrow radial extensions (6). The ring is fixed to a supporting base with saliences (4) to overcome the spaces between the laminar elements and reenterings (5) to allow its flexure. The flexure of the laminar elements is performed through a calculated progression according to a proper gradient resulting into the formation of in-between spaces (3).

Abstract: Process for the production of concrete tiles by cutting a block of concrete mixture, characterized in that the block of mixture is subjected to a preliminary curing at room temperature for a duration of at least 24 hours or to a low-pressure steam treatment at a temperature <100.degree. C. until the compression strength reaches a value of at least 20 MPa, and to a second treatment with steam in an autoclave. The cement tiles thus obtained may be bonded to the floor using a normal setting layer of cement mortar, without giving rise to any problems of detachment.

Abstract: A variable venturi carburetor is disclosed which has side walls that simultaneously are moved toward and away from one another to increase the size of the throat of the venturi as the engine speed increases and decrease the size of the throat as the engine speed decreases to provide a desirable constant air-to-fuel ratio to the engine over a range of engine speeds.