Inventors:
Peter J. Bankert - Birmingham MI
Lawrence A. Gawne - Wixom MI
Assignee:
Graco Inc. - Minneapolis MN
International Classification:
F04B 4908
F04B 4106
B05B 1208
Abstract:
A paint circulation system for supplying paint to a plurality of distributors utilizing a circulating pump to circulate paint to the distributors and an injection pump operated by a closely controlled electric motor for injecting paint into the circulation network from a paint supply reservoir to maintain a predetermined pressure within the circulation network. A "leakage" passage having a predetermined restriction permits paint to leave the circulation network when the valved paint distributors are closed, and the use of an automatic timing valve within the leakage bypass permits flow rates within the circulation network to be varied. The components permit paint viscosity and volumes to be determined, settling of the paint particles within the circulation network and degradation of the circulating paint is minimized, and circulating motor wear may be determined. Further, the invention contemplates producing an oscillating flow within dead-end drops in a paint circulation system to prevent settling in inactive conduits.