Vacuum demand flow valve

• Main Authors: WILLIAMSON, MARK E, DANBY, HAL C
• Format: Patent
• Language: English
• Published: 21.05.2003
• Edition: 7
• Subjects: ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; ACTUATING-FLOATS; BABY COMFORTERS; BLASTING; COCKS; COFFEE MILLS; CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS,e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES,DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; CONTAINERS SPECIALLY ADAPTED FOR MEDICAL OR PHARMACEUTICALPURPOSES; CONVEYING; DEVICES FOR ADMINISTERING FOOD OR MEDICINES ORALLY; DEVICES FOR RECEIVING SPITTLE; DEVICES FOR VENTING OR AERATING; DEVICES OR METHODS SPECIALLY ADAPTED FOR BRINGINGPHARMACEUTICAL PRODUCTS INTO PARTICULAR PHYSICAL ORADMINISTERING FORMS; DOMESTIC ARTICLES OR APPLIANCES; ENGINEERING ELEMENTS AND UNITS; FURNITURE; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HAND OR TRAVELLING ARTICLES; HANDLING THIN OR FILAMENTARY MATERIAL; HEATING; HOUSEHOLD OR TABLE EQUIPMENT; HUMAN NECESSITIES; HYGIENE; LIGHTING; MECHANICAL ENGINEERING; MEDICAL OR VETERINARY SCIENCE; PACKAGES; PACKAGING ELEMENTS; PACKING; PERFORMING OPERATIONS; SPICE MILLS; STORING; SUCTION CLEANERS IN GENERAL; TAPS; THERMAL INSULATION IN GENERAL; TRANSPORTING; TRAVELLING OR CAMP EQUIPMENT: SACKS OR PACKS CARRIED ON THEBODY; VALVES; WEAPONS

A valve is disclosed for dispensing a flowable material. The valve has a first chamber (40) at a first pressure wherein said first chamber (40) defines an outlet (28) in communication with said first chamber (40). A second chamber (42) is at a second pressure. The valve has a stop (18) indexed against a third pressure, operating to selectively place the first chamber (40) into communication with the second chamber (42). The stop (18) is operative to connect the second chamber (42) to said first chamber (40) when the first pressure is less than the third pressure.