Abstract: Flushable rotary gear pumps for delivering fluidic material, such as liquid coating material, may quickly and thoroughly be flushed of material of one type in preparation for delivering material of another type. In one embodiment, a valve selectively establishes a bypass channel between an inlet to and an outlet from a pump, thereby to accommodate a relatively large volume flow of flushing media through the pump and supply and delivery lines therefor. In another embodiment, the valve is structured to monitor fluid pressure developed by the pump and to automatically control and limit the pressure to a maximum value should an overpressure condition develop. In yet other embodiments passages are provided internally of the pump for conveying flushing media to all exposed surfaces of the gears, gear shafts and pump body to flush the same of coating material, whereby the entirety of the pump may readily be cleansed. If desired, the various features may be combined in a single pump.

Abstract: A flushable manifold for diaphragm protected components of a pressure transducer for sensing a flow of fluid comprises a housing having a recess therein and a diaphragm of flexible material over and closing the recess. Inlet and outlet passages communicate with the recess adjacent to and on opposite sides of its periphery, such that fluid introduced at the inlet flows through the manifold to the outlet, with the presence of fluid pressure within the manifold being detected in response to outward deflection of the diaphragm. To facilitate cleaning the manifold of fluid of one type in preparation for receiving fluid of another, one or more channels are formed in the housing within the recess in communication with the inlet and extend toward peripheral side areas of the recess to direct flushing media introduced at the inlet across all of the surfaces of the manifold and to the outlet to thoroughly clean the same.

Abstract: A color change valve structure for rotary head electrostatic spray coating systems, of the type to which a rapid rotation is imparted to a rotary spray head and coating material directed through an orifice against the head for discharge from a peripheral edge of the head in a spray, is characterized by coating material and dump valves behind the head in close proximity with the orifice. The coating material valve controls a flow of coating material from a supply line to the orifice, and the dump valve is operable to establish a passage from the supply line, through the material valve and to a dump outlet. To purge the system of coating material of one color in preparation for spraying material of another, the material valve is closed, the dump valve is opened and a flow of flushing media is established through the supply line, whereby the flushing media cleanses the supply line and material valve.

Abstract: Rotary devices for atomizing liquid coating material are characterized by a housing having a circular front wall, a generally cylindrical side wall and a plurality of circumferentially spaced passages formed therethrough in proximity with the juncture of the front and side walls. Coating material smoothly introduced into the housing onto the front or side wall is carried in a thin film by centrifugal force toward and into the passages for being projected therefrom and atomized, and an electrostatic field is established between the device and an article to be coated for electrostatic deposition of coating material on the article. The device is rotated at a relatively high speed, and the passages bring the coating material to the full rotational speed of the device as it is projected therefrom, whereby atomization and the quality of the coating on the article are improved.

Abstract: A color change system for spray coating apparatus is characterized by two pumps, each of which is connectable with a selected color of coating material for providing the same to spray coating apparatus. The arrangement is such that the pumps alternately supply different colors of coating material to the coating apparatus, and when one of the pumps is supplying material the other is being cleansed of previously supplied material. In this manner, one pump is always clean and ready for supplying a newly selected color of material, so that any number of different colors of coating material may be provided to the coating apparatus with minimum numbers of pumps, e.g., two pumps. In one embodiment the color change system is used with automatic spray coating apparatus, and in another with manual or hand held coating apparatus.

Abstract: A plural component spray gun which can be used as an air atomizing gun for atomizing material at the nozzle for external mixing with a catalyst, and, which is convertible to airless operation. The spray gun has a nozzle body which incorporates passageways for delivering atomizing air and a fluid component to a mixing chamber at the outlet to one of a plurality of nozzles attached to the nozzle body. To convert the spray gun to airless operation, the nozzles are removed, and a sleeve inserted in the air atomizing chamber. One of the nozzles is replaced with an airless type and they are reattached to the gun body. The replaced nozzle has a centrally located annular flange which extends into the air atomizing chamber to hold the sleeve insert in the chamber to seal the air passageway. The centrally located annular flange on the replaced nozzle also includes an annular cavity, into which an insert having an orifice restriction can be inserted for increasing the velocity of the component during airless operation.

Abstract: A pumping system for delivering unstable fluids under pressure, comprising a pair of alternately operated single-acting pumps operated by a double-acting air motor. The air motor is controlled by a reversible spool valve and mechanically operated air pilot valves. The single-acting pumps deliver and contain relatively small quantities of the unstable fluid to a positive flow metering system for connection to an outlet to spray guns or other equipment using the fluid. The metering system includes a metering valve, a flow meter and a bypass valve for removing trapped air and presetting flow.

Abstract: An adjustable pressure control device relies on the change of shape or position of a control hose portion responsive to internal pressure of fluid being transmitted therethrough to control the fluid pressure produced by a pump. One embodiment of the device utilizes a short piece of high pressure hose in the fluid line which is adjustably deformed. As pressure builds up in the hose, the hose tends to return to its original shape, thereby actuating a suitable control instrumentality for the pump, such as an electric switch which opens the circuit to an electric clutch or to an electric drive motor for the pump, thereby temporarily stopping the pumping action. Another embodiment, to accomplish the same function, relies on the change of the arcuate position of a control hose due to variations in fluid pressure therein.

Abstract: A safety cover for rotary head electrostatic spray coating systems, of the type to which a rapid rotation is imparted to a rotary spray head and a jet of coating material to be sprayed directed thereagainst for discharge from a peripheral edge of the head in a spray, is characterized by a cover movable between positions over and around the head and remote from the head, and a mechanism for moving the cover. When positioned over the head, the cover protects nearby personnel against accidental injury resulting from contact with the rapidly rotating head, and at the same time serves as a receptacle for receiving and containing solvent and residual coating material discharged from the head when the same is cleaned, as for example during color changes when coating materials of different colors are sprayed.

Abstract: An air washer or scrubber, particularly for paint spray booths and especially adapted for removing paint particles from air passing downwardly through the grille floor of a paint spray booth and against a water-washed subfloor, comprises an elongated V-shaped slot in the subfloor extending along the longitudinal centerline of the booth. The inner edges of the walls forming the V-shaped slot are upturned to form ledges so that water flowed over the subfloor and the walls of the slot impinges against the ledges and is thrown upwardly and inwardly to form a curtain of water completely covering the slot. Exhaust means pulls paint-laden air from the spray chamber through the water curtain and the slot and into an expansion chamber, the bottom walls of which form a second V-shaped slot contiguous with the first mentioned slot.

Abstract: A system is provided for extinguishing accidental fires in paint spray booths of the type wherein oil is used as the medium for eliminating extraneous paint mist and overspray, said system providing control over both the oil and the medium used for extinguishing the fire. In such a spray booth, oil from a self-contained reservoir located at the bottom of the booth is circulated over a plurality of baffles within the booth. Paint mist is drawn by flow of air into contact with the oil covered baffles, and the paint solids are thereby entrained in the oil and collected in the oil reservoir. An appropriate fire extinguishing system for such spray booth comprises a plurality of water fog nozzles within the booth that are activated in response to a fire, and which therefore discharge water into the reservoir.

Abstract: A power supply for generating a high unidirectional voltage at a charging electrode of an electrostatic spray coating apparatus has circuitry for sensing the magnitude of current flow to the electrode and for controlling application of an input voltage to the power supply in accordance therewith to control the magnitude of the high voltage. The arrangement is such that whenever the current flow is less than a predetermined value all cycles of the input voltage are applied to the power supply, but whenever the current exceeds the predetermined value only a limited number of the cycles are applied to the power supply. In this manner, the danger of arcing between the electrode and an article being coated is eliminated or at least significantly reduced.

Abstract: Air or other gases containing contaminants or requiring treatment are moved into at least one substantially continuous sheet of treating liquid at the entrance to a streamline flow passage. A nozzle mounted adjacent the entrance end of the flow passage forms one or more substantially continuous solid sheets of treating liquid covering the entrance to the passage. The passage has a convex throat and an exit smaller than the entrance so that the gas and treating liquid entrained therein move through the passage at an accelerating velocity with smooth, non-turbulent, unidirectional flow, and are discharged therefrom with no discernible turbulence or splashing. The gas and the treating liquid are discharged from the flow passaage into an eliminator chamber of large volume, whereupon the treating liquid and any entrained contaminants drop out of and are separated from the gas.

Abstract: An improved pump for fluid is characterized by one or more turbine pumping stages each having outlet ports configured to provide a constant fluid pressure from the pump for various flow rates of the fluid. The stages are connectable in series so that each increases the pressure of the pumped fluid by a predetermined amount, and each includes a housing having a pumping chamber with an inlet thereto and outlet ports therefrom, and an impeller rotatable in the chamber to move ends of blades thereof past the ports. The ports are uniquely configured to have fluid flow areas which increase with increasing distance from the chamber, whereby the pressure of the pumped fluid remains substantially constant for all flow rates of the fluid up to a design flow rate, and a fluid bypass port of adjustable flow area is provided in at least one of the pumping stages for controlling the pressure of the fluid at an outlet from the pump.

Abstract: An electrostatic spray coating apparatus including means for mechanically atomizing coating materials and means for electrostatically charging the atomized material for deposit onto articles, is characterized by an improved material-charging means and an improved means for sealing material passages from the remainder of the apparatus in a manner which contributes to efficient and effective charging of the material, yet minimizes the capacitance of the material charging means, whereby the energy capable of being stored by the charging means is significantly reduced. The spray coating apparatus also includes means ensuring safety of the apparatus, and enhanced overall construction of the apparatus for greater service life, more reliable and safe operation, and economy.

Abstract: An adjustable pressure control device relies on the change of shape or position of a control hose portion responsive to internal pressure of fluid being transmitted therethrough to control the fluid pressure produced by a pump. One embodiment of the device utilizes a short piece of high pressure hose in the fluid line which is adjustably deformed. As pressure builds up in the hose, the hose tends to return to its original shape, thereby actuating a suitable control instrumentality for the pump, such as an electric switch which opens the circuit to an electric clutch or to an electric drive motor for the pump, thereby temporarily stopping the pumping action. Another embodiment, to accomplish the same function, relies on the change of the arcuate position of a control hose due to variations in fluid pressure therein.

Abstract: A pump, characterized by flexible tubes which are cyclically expanded and contracted to cause fluid to be pumped, comprises a pair of liquid filled cylinders each containing a flexible tube connected to inlet and outlet valves, a liquid filled control cylinder communicating at its opposite ends with respective ones of said pump cylinders, and a piston reciprocable in said control cylinder for alternately transferring fluid to and from said pump cylinders for alternately and cyclically expanding and contracting said tubes to cause fluid to be pumped in a double acting pump action. The pump is especially well suited for pumping abrasive and corrosive slurries, heavily pigmented and/or metal filled coating materials and the like. The pump is characterized by improved piston means, improved sealing and retaining means for both the piston and the tubes, and means for detecting leakage across the piston, whereby to increase pump reliability and longevity of service, and to monitor internal pump conditions.

Abstract: An improved paint spray gun assembly of the syphon type having a vented paint supply container, is characterized by a conduit connectable either between the container vent and a compressed air inlet to the gun, or between the vent and a fitting remote therefrom and open to atmosphere. With either connection, the conduit prevents dripping of paint from the vent upon manipulation of the gun by an operator, and with the connection of the vent with the compressed air a positive pressure is generated within the container to increase the paint flow rate from the gun.

Abstract: An improved paint spray gun assembly of the syphon type having a vented paint supply container, is characterized by a conduit connectable either between the container vent and a compressed air inlet to the gun, or between the vent and a fitting remote therefrom and open to atmosphere. With either connection, the conduit prevents dripping of paint from the vent upon manipulation of the gun by an operator, and with the connection of the vent with the compressed air a positive pressure is generated within the container to increase the paint flow rate from the gun.

Abstract: A traveling paint spray booth is movable on rails beneath a stationary exhaust duct extending longitudinally of the rails. The bottom of the stationary duct is formed by a plurality of dampers pivotable to open and closed position on a hinge having its axis extending longitudinally in the duct and protected by an air deflector. The booth is provided with damper openers which engage the body portion of successive dampers to open them as the booth passes therebeneath.