Abstract: A paint spray booth apparatus and method, particularly for automated paint applications, is illustrated and disclosed. The booth has a spray painting chamber and a plenum thereabove. Unlike prior art booths, the plenum of the present invention provides air flow only where needed to control overspray, and generally the plenum is only 60%, or less, in width or cross-section than the prior art, full ceiling width plenums. In carrying out the method of the present invention air is supplied from the plenum to the spray painting chamber only where needed to control overspray so that consequently the quantity of air utilized is substantially less than in prior art booths with air flow from their full width plenums. In certain booths where painting occurs on both sides of the booth, it is advantageous to provide the plenum in the form of two or dual plenums, each offset from the center of the booth.

Abstract: A system for improving the viscosity of coating materials comprised of coaxial hoses inserted in a coating material supply hose. A heating fluid is continuously circulated through the coaxial hoses to heat a thin film of coating material in the supply hose. The heating fluid, preferably deionized water, heats the coating material to a preselected temperature to provide optimum viscosity for highest coating efficiency. An emulsifier added to the heating fluid improves heat retention and flow rates by improving lubricity. The coaxial hose heating system is connected to the coating material through a coupling and distributor block that allows easy removal for repair, replacement or use without the hose heater.

Abstract: A recirculating washer for a paint spray booth is illustrated and described, and uses upward air motion and gravity to recirculate water on and along two or more recirculating baffles facing each other to form one or more curtains of water for cleaning paint laden air from the pain spray booth. The washer's baffles direct the water to form the curtains. The recirculating washer may be used in a booth by itself, or with one or more washers of another type washer, such as a slot type and/or an air nozzle-water nozzle type washer to reduce the amount of water required by the booth. The washer may use the other type washer or a trough for cource of the recirculated water. Preferably, the washer utilizes the floor water from the booth so that the water requirement for the entire booth is very low, say on the order of 40 gallons per minute per foot of booth length, or less, for a booth of a size capable of production line painint of automotive vehicles.

Abstract: A paint spray booth, which can also be utilized as a paint drying oven is disclosed and is especially suitable for use in businesses, such as automobile repair shops, to both paint and quickly bake the paint so that the number of automobiles that may be handled in a given time is increased significantly. The booth-oven comprises an enclosure which has a single air supply fan for moving air though the booth-oven. Preferably, the booth-oven has, in addition to a direct heater, a heat exchanger for more economical operation, and/or may be provided with an air recirculating system for additional savings. The booth-oven is structured so that paint laden air generated during the paint spraying operation is routed around or away from the heat exchanger.

Abstract: Color change systems for electrostatic coating apparatus are characterized by a dielectric manifold in-line between supplies of different colors of coating materials and a material supply line to the apparatus. To initiate a coating operation, a selected color of material is provided through the manifold to fill the supply line, whereafter the manifold is flushed clean of the material. A high electrostatic charging voltage is then applied to the coating apparatus while the material in the line is supplied to the apparatus for being electrostatically charged and emitted by the apparatus to coat an article. For conductive coating materials, during the coating operation the high charging voltage conducted through the material in the hose is blocked by the nonconductive dielectric manifold and cannot reach and charge the material supplies, so there is no need for a protective enclosure around the supplies of leakage of charging current to the supplies.

Abstract: An electrostatic spray coating system has a reservoir into which a metered quantity of electrically conductive paint is flowed from a grounded color changer and through a first flow meter. After filling the reservoir, at least a portion of the flow path between the reservoir and the color changer is cleaned of paint to electrically isolate the reservoir and paint therein from the color changer. The paint in the reservoir is then flowed through a second flow meter to an electrostatic spray gun. The second flow meter is electrically isolated from ground and is used to compare the quantity of paint delivered to the spray gun to the quantity of paint loaded into the reservoir, as well as to monitor and control the volume flow rate of paint from the reservoir to the spray gun. The arrangement makes it possible to spray substantially all of the paint flowed into the reservoir and to accurately control the flow rate of paint to the spray gun.

Abstract: A low friction proportional unloading valve mechanism for pressurized fluid circuits incorporating a valve housing forming primary and bypass fluid circuits. A normally closed unloading valve normally prevents the flow of incoming fluid to the bypass fluid circuit and is opened by a pressure responsive valve actuator. The valve actuator forms a pressure responsive wall and may take the form of spaced diaphragms or a deformable flexible hose that induces opening force to the unloading valve in direct proportion to the pressure in the primary fluid circuit. upon opening of the unloading valve, a check valve in the primary fluid circuit prevents back flow and thus maintains valve controlling pressure on the movable wall structure of the valve actuator.

Abstract: A pump assembly especially adapted for pumping viscous and/or abrasive materials is comprised of a pair of opposed single acting piston pumps operated alternately by an interposed reciprocal actuator, and a static chamber interposed between each pump and the actuator; each pump comprising a pumping chamber having aligned inlet and outlet check valves in its peripheral wall and defining a straight line path of fluid flow diametrically through the chamber, a piston having its periphery spaced from the peripheral wall of the pumping chamber and having a relatively short stroke to maintain the straight line path of fluid flow through the chamber, and an annular seal extending from the peripheral wall of the pumping chamber toward the piston and bridging the gap between the periphery of the piston and the peripheral wall of the pumping chamber, the piston having sealed engagement with the seal throughout its reciprocal path of movement; the static chambers isolating the two pumps and the actuator from one another

Abstract: An improved fluid valve stem for an air spray gun has a triangular-shaped forward end extended into a cylindrical fluid outlet passage of a fluid nozzle. The triangular-shaped forward end forms liquid coating material flowing therepast into a hollow cylindrical stream that is emitted from the fluid nozzle and pneumatically atomized into a spray. The hollow stream of coating material is considerably easier to atomize than is a solid stream, so with the result that effective atomization is achieved at low air pressures and volumes for improved transfer efficiency.

Abstract: An improvement for a production line, downdraft type paint spray booth having a conveyor for carrying the parts to be painted, having a recessed portion for containing the conveyor and dual slots, on one or either side of the conveyor for air flow is disclosed.The improvement provides the advantage of improved air flow around the parts being painted and around the conveyor to keep it clean. Additionally, the provision of the dual slots permits the conveyor to be at least partially recessed into the booths floor to provide a lower profile and a more compact arrangement.

Abstract: A high volume low pressure air spray gun has an atomizing air orifice for atomizing a stream of liquid coating material into a conical spray and opposed side port air orifices for flattening the spray into a fan-shaped pattern. The gun receives air at pressures up to about 100 psi, and an air flow restriction in the form of a venturi is in an air supply passage in the gun barrel. A valve stem for controlling the flow rate of air to the side port orifices extends through the venturi, and is configured to vary the venturi air flow area in response to changes in the flow rate of air to the side port orifices. When the valve stem is positioned for maximum air flow to the side port orifices, it establishes a maximum air flow area through the venturi, such that a high pressure of air at the gun air inlet, after flowing through the venturi, results in a high volume low pressure air flow at the atomizing and side port orifices.

Abstract: A painting structure for use as, by way of example, a paint spray booth or paint baking or drying oven, utilizes a trapezoidal cross-section, instead of the conventional rectangular/square or rectangular-gabled cross-section. The painting structure of the present invention provides inherent rigidity without the need for special framing, and provides more uniform air flow than a gabled roof structure, as air swirls in air pockets beneath the gables are eliminated. Due to the simplified construction, the trapezoidal cross-sectional booth of the present invention is less expensive to make and install and more easily erected.

Abstract: A structure and a filter suitable for a paint spray booth, oven, or a combination booth and oven is described and includes outer walls enclosing the structure, only a portion of which provides the structural support for the booth's walls and roof. The interior of the booth has a plurality of filters on the walls and ceilings for supplying air from essentially the walls and ceiling to provide a more uniform air flow so that the painter is less exposed to vaporizing solvents, and when used as an oven, the heating is more uniform. Each of the filters made of a cloth material held in place by filter frames and may be used with either battens fixed to the frames or removable and held in place in pockets provided in the filter cloth.

Abstract: A pressure responsive driver couples a reciprocating motor output to a reciprocable piston of a double-acting pump. In one embodiment, the driver comprises a single spring and in another a pair of springs, which transfer reciprocation forces of the motor output to the piston to reciprocate the piston through its pumping strokes. The spring(s) transfers the entirety of the reciprocation forces of the motor output to the piston until a selected outlet pressure from the pump is reached, whereupon the spring(s) compresses to absorb cranking forces and limit maximum pump outlet pressure to about the selected pressure. The reciprocating motion of the motor output is divided between the spring(s) and piston, such that the extent of flexure of the spring(s) is inversely proportional to movement of the piston, whereby the spring(s) takes up any motion of the motor output not used to move the piston.

Abstract: A positive displacement flushable flow meter has sensing elements that are rotated by and at a rate in accordance with a flow of fluid through the flow meter. The flow meter is particularly adapted for measuring the volume flow rate of coating material supplied to spray coating apparatus, and to permit the flow meter to be quickly flushed by means of alternate bursts of relatively high velocity air and solvent, without overdriving the sensing elements and damaging the flow meter, a bypass valve is provided. During a spray coating operation, the bypass valve is closed and all of the coating material flows past and rotates the sensing elements. During a flushing operation, the bypass valve is opened to divert some of the relatively high velocity flow of air and solvent around the sensing elements, while allowing a controlled and limited amount of air and solvent to move past and rotate the elements to clean them without causing them to be overdriven.

Abstract: Apparatus for coupling a grounded color changer and associated supplies of conductive paint to an electrostatic paint sprayer isolates the color changer and paint supplies from a high voltage at the sprayer. The apparatus has at least one reservoir into which a metered volume of one color of paint to be sprayed is introduced while the reservoir and its contents are grounded. After charging the reservoir with paint and prior to supply of the paint to the sprayer, fluid lines between the reservoir and color changer are flushed to electrically isolate the reservoir and paint therein from the color changer and paint supplies. The reservoir and paint therein are then ungrounded and the paint is delivered to the sprayer for being emitted in an electrostatically charged atomized spray. At the end of spraying, the high voltage is removed from the sprayer and the reservoir and its contents are again grounded, following which the reservoir is purged of paint of the one color and reloaded with paint of another color.

Abstract: A plural component air spray gun is characterized by a spray head assembly that has a pair of hemispherically shaped fluid outlet orifices, the straight sides of which are facing, parallel and separated by a relatively thin wall. Each orifice receives a respective one of two liquid materials delivered through associated liquid supply passages, and the passages are inclined so that streams of liquid emitted from the orifices come together a short distance beyond the orifices. Air emitted from an atomizing air orifice surrounding the two fluid orifices mixes and breaks up the liquid material streams into an atomized conical spray. To form the conical spray into a fan-shaped pattern, an air cap directs air jets against opposite sides of the spray.

Abstract: A modular color changer provides selected paint colors for spraying and recirculates nonselected colors. A module is provided for each paint color to be selected, and each module has an inlet for connection with a respective supply of paint, a recirculate outlet, a delivery outlet and a single valve member. The valve member may be selectively engaged with either a first or a second seat, depending upon whether paint at the inlet is to be directed to the recirculate outlet for return to the supply or to the delivery outlet for flow to a paint applicator. Solvent and air purge valves are upstream of the modules for cleaning the color changer of one color of paint in preparation for supplying another.

Abstract: A system and device for adding dry media to a liquid stream or fan-shaped spray of paint or other suitable liquid material emerging from a spray gun. The dry media are added to the liquid stream by connecting a nozzle spray guard having hose connectors with injectors on opposite sides of the guard. The injection jets are constructed to add dry media at between 45 degrees and 90 degrees to the liquid stream exiting the nozzle of the spray gun. Wing-like appendages on the nozzle guard assist in containing the granular material in the path to impinge on the liquid stream. The liquid stream containing the uniformly mixed dry media or granular material is sprayed on the surface to which it is being applied.

Abstract: A system for purging fluid delivery systems such as paint spray guns with non-toxic, non-polluting cleaning solvents. A sealed tank is provided for storing a cleaning solvent with air pressure applied to deliver the cleaning solvent through a coaxial hose to a slide selectable valve. Pressurized air is also connected to one of the conduits of the coaxial hose. Spray guns or fluid delivery systems are cleaned and purged by first releasing the cleaning solvent in the passageways and then quickly switching to a blow-down mode on the slide selectable valve to discharge the cleaning solvent from the spray gun passages.