Abstract: A hot melt adhesive dispensing system that includes a hand held gun and a molten adhesive source, the gun and the source being selectively connectable one with the other in a novel manner to permit charging and recharging of the gun with molten adhesive from the molten adhesive source. The hand gun includes novel charge valve structure adapted to interconnect with novel feed valve structure mounted on the hot melt adhesive source so as to accomplish transfer of a hot melt adhesive charge in molten form, from the source to the gun storage chamber. The adhesive is pressurized within the gun's storage chamber by a novel pressure device at least partially incorporated within the storage chamber, thereby providing the motive force to cause discharge of molten adhesive from the gun's nozzle in response to manual activation of the gun's trigger.

Abstract: A hot melt adhesive foam pump system having a first stage pump that meters molten hot melt adhesive into a second stage pump, which in turn mixes gas under pressure into the adhesive so that the gas is driven into solution with the adhesive at an adjustably controllable ratio. The pump is insensitive to changes in adhesive viscosity and pump speed, and provides uniformity of foam density and output flow rate when the adhesive is ejected from a dispenser connected to the pump.

Abstract: A gear pump for dispersing a gas into a liquid is provided with mixing means for improving the uniformity of the dispersion. In preferred form, the mixing means comprises a series of fixed, shallow, blind cavities that open to the pumping cavity between the liquid inlet and the outlet, and which are positioned to be "wiped" by the gear teeth as the gears rotate. The alternate connection and disconnection of the intertooth spaces to these cavities as the gears rotate establishes motion or turbulence of the gas/liquid mixture within the intertooth spaces, and surprisingly improves uniformity of the dispersion.

Abstract: A hot melt adhesive dispensing system that includes a hand held gun and a molten adhesive source, the gun and the source being selectively connectable one with the other in a novel manner to permit charging and recharging of the gun with molten adhesive from the molten adhesive source. The hand gun includes novel charge valve structure adapted to interconnect with novel feed valve structure mounted on the hot melt adhesive source so as to accomplish transfer of a hot melt adhesive charge in molten form, from the source to the gun storage chamber. The adhesive is pressurized within the gun's storage chamber by a novel pressure device at least partially incorporated within the storage chamber, thereby providing the motive force to cause discharge of molten adhesive from the gun's nozzle in response to manual activation of the gun's trigger.

Abstract: Apparatus for dispensing hot viscous liquids such as molten adhesives, either in a continuous bead or as spaced unitary deposits. In preferred form, the apparatus includes a heat exchanger in the form of a fluid manifold which functions to elevate and maintain the temperature of the molten adhesive, just prior to dispensing it, above that temperature level at which the molten adhesive is supplied to the apparatus.