Abstract: A gate for controlling passage through an opening including a first support located on one side of the opening, a second support located on the other side of the opening, at least one elongate member, having a first and a second end, extendable across the opening between the first and second support; and a control for releasing the at least one elongate member to whereby enable passage through the opening and drawing in the elongate member to thereby restrict passage through the opening.

Abstract: The present invention provides hollow borosilicate microspheres having a mean particle size between 15 and 20 microns, and a true density below 0.25 g/cc. The invention also provides a method for making such microspheres comprising spray drying a solution of sodium silicate and sodium borate in a spray tower to form a precursor, milling the precursor, and heating the crushed precursor to a temperature in excess of 600.degree. F. to form hollow borosilicate microspheres.

Abstract: A fuel injection system for a multi-cylinder internal combustion engine, which includes a rigid elongated unitary member incorporating a gas supply duct, a fuel supply duct and a fuel return duct, each of which extends in the direction of elongation of the unitary member. A separate fuel metering device and fuel injecting device is provided for each engine cylinder. The fuel metering device is arranged to deliver metered quantities of fuel to the fuel injection device and is in communication with the fuel supply and fuel return ducts so that fuel can be circulated through each of the fuel metering devices. The fuel injecting devices are each in communication with the gas duct and communicable with one of the engine cylinders. The fuel injection devices are adapted to effect delivery of a metered quantity of fuel entrained in gas supplied from the gas duct when the fuel injecting device is in fluid communication with a cylinder.