Abstract: The present invention relates to a pump for transferring liquids, in particular for beer or carbonated beverages, characterized in that it is constituted by two mutually opposite and integral pistons sliding inside two cylinders which generate, with their reciprocating motion, four variable-volume chambers inside two of which the fluid, through suitable valves, is alternatively intaken and delivered by a gas whose pressure is modulated by a suitable pressure regulator, in which it is the pressure of the same delivered liquid to counteract the calibration force, with said gas alternatively going to act, by means of suitable control means, inside the chamber behind the delivery chamber, so that the delivery pressure of the same liquid remains constant and predetermined, wherein said delivery pressure is obtained as the sum of the thrust of the liquid intaken from the opposite chamber, plus the modulated gas pressure, which acts on the rear face of the delivery piston.

Abstract: A method of and apparatus for the electrostatic application of a coating material on a product of either electrically conducting or non-conducting material. The product is caused to descend from a hopper (10) in free fall in the form of spaced curtains (28, 30) across two streams (40, 42) of electrostatically charged coating material directed laterally of the curtains from opposite sides thereof. The rate of flow and spacing of the curtains (28, 30) is adjustable (32, 14, 16, 18, 20, 22, 26) as required depending upon the nature of the product and the properties of the coating material. Charges of opposite polarity are applied respectively to the two streams with the result that an electrostatic charge opposite to that of a stream is imparted to that side of each of the two curtains towards which the stream is directed causing attraction between the coating material and the product. The uniformity of the applied coating is much improved as compared with conventional techniques.