Spray gun with barrel-mounted venturi

US5671888A · kind A · utility

Inventor

• Paul Michael Smith · Toronto, CA

Key dates

• Filing date: Jan 20, 1995
• Grant date: Sep 30, 1997
• Expiry date: Jan 20, 2015

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B05B7/0815
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A high-volume, low-pressure spray gun operates from a conventional high pressure compressor. The gun has a barrel that supports a spray head, a handle that extends downwardly from the barrel, an inlet port at the bottom of the handle for receiving compressed air, and a passage in the handle directing compressed air toward the barrel. A venturi is mounted within the barrel and discharges a stream of compressed air downstream toward the spray head. The venturi entrains ambient air through orifices in the barrel. A valve mounted within the handle and operated with a trigger controls the flow of compressed air through the gun. The venturi is entirely separate from the trigger and the valve, and no complex linkage couples the trigger and valve, greatly simplifying construction. The venturi may be sealed to the passage in the handle to receive compressed air, and may be spaced from the barrel to allow entrainment of ambient air from the rear of the barrel.