MODULAR FOAM DISPENSER

摘要

A dispenser for mixing foam precursor chemicals and dispensing the foamable mixture includes a first module (28) containing shutoff valves (42, 44) and a second module (30) containing a dispensing valve assembly (54). The dispensing valve (54) assembly includes a valve body (82) of a self-lubricating material and a valuing rod (56) which is reciprocatingly retracted in a valve passage (84) of the valve body (82) to uncover orifices (86, 88) which supply the precursor fluids into the valve passage (84), from which the mixed chemicals are dispensed. The dispensing valve (54) assembly includes a die spring (94) which urges a washer (90) to compress the valve body (82) along its axis to help prevent cold flow of the valve body away from the valuing rod (56). The valuing rod is scraped by inner surfaces of the hole (92) in the washer (90) through which the valuing rod (56) is retracted and extended. The die spring (94) is preloaded and retained by a load cylinder (96) which is fixed in the bore (52) in the second housing (50) which contains the dispensing valve (54). An end portion of the load cylinder (96) extends from the bore (52) and carries a thrust ring (180) which engages grooves (184) in the first and second housings (32, 50) for preventi ng relative movement between the two modules (28, 30) alongthe axis of the bore (52). A cap (72) secured within the dispensing end of the bore (52) forms an annular solvent receiving chamber (190) surrounding an end portion of the valuing rod (56). The valuing rod tip (186 ) is rounded and is exposed to the annular chamber (190) when the valuing rod (56) is in a non-dispensing position, so that solvent flowing into the annular chamber (190) flows outwardly over the tip (186) to clean foam chemicals therefrom. The cap outer face (198) and ro d tip (186) are coated with a release material such as TFE.