Patent ID: 6311723
Filing Date: 2001-11-06
Classification: G05D,Y10T

Abstract:
A fluid flow control valve mountable on a container to be filled with fluid, the fluid flow control valve comprising:a valve body;a first chamber in the valve body connected at or adjacent an upstream end to a fuel inlet, the fuel inlet being connectable to a source of fluid under pressure, the first chamber having a plain bore defined by a cylindrical wall and closed at a downstream end by an end wall;a second chamber in the valve body connected to a fluid outlet, the fluid outlet being connectable to the container to be filled with fluid, the second chamber at least partially surrounding the cylindrical wall of the first chamber;at least one fluid passage or fluid port through the cylindrical wall interconnecting the first and second chambers;a bleed passage in the cylindrical wall of the first chamber, having a bleed passage inlet in the end wall of the first chamber and a bleed passage outlet connectable to a remote fluid level sensor in the container;a piston, having at least one bleed port therethrough, slidably received in the plain bore of the first chamber; anda resilient member urging the piston to a first position where a side wall of the piston closes the fluid passage(s) or fluid port(s) through the cylindrical wall of the first chamber; so arranged that:when the fluid level sensor senses that a fluid level in the container is below a pre-set level, a portion of the fluid from the fluid inlet is bled through the bleed port(s) in the piston and through the bleed passage, to enable a fluid pressure difference between the upstream and downstream ends of the first chamber to move the piston to a second position, against the resilient member, allowing the fluid to flow from the fluid inlet, through the upstream end of the first chamber, through the fluid passage(s) or fluid port(s), and then through the second chamber to the fluid outlet; but when the fluid level sensor senses that the fluid level has reached or exceeded the preset level, the fluid level sensor shuts off the fluid flow through the bleed passage to equalize the pressure on both ends of the piston in the first chamber, and the resilient member urges the piston to the first position to shut off the flow of fluid from the fluid inlet to the fluid outlet and thereby the fluid flow from the fluid source to the container, closure of the fluid passage(s) or fluid port(s) by the side wall of the piston, when the piston is in the first position, preventing backflow of the fluid from the fluid outlet to the fluid inlet, if the fluid pressure at the fluid outlet exceeds the fluid pressure at the fluid inlet.