Abstract: Apparatus for dispensing a mixture of mutually reactive liquids, such as a resin and its hardener, comprises a gun head having a bore opening therethrough to define a mixing chamber. The mutually reactive liquids are fed along separate paths through the head and into the bore to mix in the bore and be dispensed through one end of the bore. A valving rod is reciprocable in the bore, between a forward position in which the valving rod seals the liquid inlets from each other and occupies the mixing chamber, and a rearward position in which the valving rod opens the mixing chamber and permits the flow of liquids into the mixing chamber. One of the liquids is fed along the outer surface of the valving rod in the retracted position of the valving rod and along most of the length of the valving rod which was disposed in the mixing chamber in the forward position of the valving rod. In this way, mixed liquids are washed from the valving rod by that one component, in the rearward position of the valving rod.

Abstract: A coupling for conduits through which passes a liquid that must be kept from spilling and/or from being exposed to the air, comprises a pair of parallelepipedal blocks in each of which is disposed a ball valve. Two flat faces of the blocks mate, whereupon the blocks are releasably secured together by bolts. The ball valves are disposed as close as possible to the mating interface of the blocks; and the liquid passageway that opens through the mating faces is surrounded by an annular bevel. Each ball valve has an operator whose rotation through 90.degree. between open and closed valve positions is predetermined by a pin on the operator that engages one or the other face of a recess milled in the block. A pin disposed in a hole in the block is disposed in an annular groove in the valve operator to retain the operator in the block.

Abstract: Apparatus for dispensing a mixture of mutually reactive liquids, such as a hardenable plastic foam, comprises a metal housing with a plastic mixing chamber disposed in the housing and having a bore therethrough in which a purging rod reciprocates to clean reactive mixture from the bore. The reactive liquids are separately introduced into the bore through the mixing chamber via valve assemblies whose metal housings extend through the plastic mixing chamber and terminate at the bore. The purging rod retracts rearwardly into a scraper that is immediately behind the inlet openings for the liquids, the scraper being disposed in a recess in the rear of the plastic mixing chamber. The plastic mixing chamber is compressed rearwardly, so that it seals against the valve housings and the scraper. Also, the valve housings have a crush fit with the plastic of the mixing chamber, to augment the seal.

Abstract: A feeder for apparatus for ejecting a mixture of liquids, e.g. urethane foam, comprises a pair of swash plate proportioning pumps one individual to each of the liquids, e.g. resin and isocyanate, each proportioning pump being fed by a gear pump from a supply of the respective liquid. Seepage along the drive shafts of the isocyanate pumps is continuously removed by bathing them in a recirculating stream of flushing agent. The swash plate and gear pumps and flushing agent pump are all driven by a single motor from a common chain drive. The liquids are heated during passage through separate hoses to a common dispensing head or gun, by immersed coil electric resistance heaters extending lengthwise freely within the hoses. A novel control system is provided for the hose heater circuit, the adequacy of the liquid supply and other operating conditions.

Abstract: A feeder for apparatus for ejecting a mixture of liquids, e.g. urethane foam, comprises a pair of swash plate proportioning pumps one individual to each of the liquids, e.g. resin and isocyanate, each proportioning pump being fed by a gear pump from a supply of the respective liquid. Seepage along the drive shafts of the isocyanate pumps is continuously removed by bathing them in a recirculating stream of flushing agent. The swash plate and gear pumps and flushing agent pump are all driven by a single motor from a common chain drive. The liquids are heated during passage through separate hoses to a common dispensing head or gun, by immersed coil electric resistance heaters extending lengthwise freely within the hoses. A novel control system is provided for the hose heater circuit, the adequacy of the liquid supply and other operating conditions.

Abstract: A feeder for apparatus for ejecting a mixture of liquids, e.g. urethane foam, comprises a pair of swash plate proportioning pumps one individual to each of the liquids, e.g. resin and isocyanate, each proportioning pump being fed by a gear pump from a supply of the respective liquid. Seepage along the drive shafts of the isocyanate pumps is continuously removed by bathing them in a recirculating stream of flushing agent. The swash plate and gear pumps and flushing agent pump are all driven by a single motor from a common chain drive. The liquids are heated during passage through separate hoses to a common dispensing head or gun, by immersed coil electric resistance heaters extending lengthwise freely within the hoses. A novel control system is provided for the hose heater circuit, the adequacy of the liquid supply and other operating conditions.

Abstract: A feeder for apparatus for ejecting a mixture of liquids, e.g. urethane foam, comprises a pair of swash plate proportioning pumps one individual to each of the liquids, e.g. resin and isocyanate, each proportioning pump being fed by a gear pump from a supply of the respective liquid. Seepage along the drive shafts of the isocyanate pumps is continuously removed by bathing them in a recirculating stream of flushing agent. The swash plate and gear pumps and flushing agent pump are all driven by a single motor from a common chain drive. The liquids are heated during passage through separate hoses to a common dispensing head or gun, by immersed coil electric resistance heaters extending lengthwise freely within the hoses. A novel control system is provided for the hose heater circuit, the adequacy of the liquid supply and other operating conditions.

Abstract: Apparatus for ejecting a mixture of liquids, e.g. urethane foam, comprises a cylindrical chamber into which the liquids are separately introduced under pressure and mixed and ejected from the open end of the chamber. A reciprocable plunger alternately exposes the inlets in its rear portion and seals the inlets from each other and purges the chamber in its forward position. The inlets are axially spaced apart and separated from each other by a throat that has interference fit with the plunger in the forward position of the plunger, the plunger having for this purpose an elastic deformable surface.