Constant pressure intermittent fluid dispenser.

摘要

A constant pressure dispenser for intermittently dispensing pressurized molten hot melt adhesives from a source thereof. The dispenser includes a service block connected directly to the source. Dispensing and return gun modules are mounted to the service block. A return hose connects the return gun module to the source. A valve element, controlled by a control fluid, is operative on the dispensing and return gun modules so as to regulate the operation of the gun modules. The gun modules being in either an "on" or an "off" condition alternately.
<??>In the "on" condition, the valve element allows adhesive to be dispensed by the dispensing gun module and prevents adhesive from being dispensed by the return gun module. In the "off" condition, the valve element prevents adhesive from being dispensed by the dispensing gun module and adhesive is allowed to flow through the return gun module and back to the source so that a constant pressure is maintained within the dispensing gun module whether the modules are in an "on" or an "off" condition.