The outlet tubes of pressurized cans containing, for example, polyurethane which is to be foamed, very frequently become clogged. The unconsumed residue of the substance intended to be dispensed consequently becomes unusable. This is prevented in accordance with the invention by the use of tubes which...http://www.google.ca/patents/US5549226?utm_source=gb-gplus-sharePatent US5549226 - Device for operating devices for propellant cans
