Automatic solvent injection for plural component spray gun
AssigneeGraco Minnesota Inc.
InventorsRichard D. Anderson, Joseph E. Tix, Jeffrey N. Velgersdyk
Life of this patent
Estimating the term…
Abstract
A solvent piston 22 shuttles between first and second positions. In the first position, high pressure air applied to the rear 22a of the solvent piston 22 closes a solvent bore 24 around the solvent piston 22 and prevents passage of solvent into the mix chamber 26. In the second position, high pressure air is applied to the front 22b of the solvent piston 22 causing it to retract slightly thereby uncovering the solvent bore 24, closing off the solvent inlet 28 and allowing a slug of solvent to mix with the purge air 32 and pass from the solvent outlet 30 into the mix chamber 26. The solvent is either self contained in the applicator or plumbed eternally to the gun.
Claims1
A plural component spray gun having a mix chamber and a purge air passage, the improvement comprising:
- a source of solvent;
- and
- a solvent piston having a front and a rear and movable between a first non-spraying position and a second spraying positions such that in said first position, high pressure air is applied to said rear to close a solvent bore connected to said solvent source to prevents passage of solvent into said mix chamber and in said second position, high pressure air is applied to said front on detriggering said gun causing it to retract uncovering said solvent bore, closing off said solvent inlet and allowing a slug of solvent to mix in said purge air passage and pass from said solvent outlet into said mix chamber
Dependencies are inferred from the claim text.