Abstract: Method and apparatus for charging powdered particles and delivering only these charged particles to a workpiece. A high voltage electric field is created between upper and lower surfaces. Powder is continuously delivered to the lower surface. The lower surface is vibrated to bounce the particles so that each repeatedly contacts the lower surface and picks up an electrostatic charge with each contact. When the charge from the particle is great enough to overcome gravity, the particle levitates and is thereafter transported to a workpiece, where it adheres by electrostatic attraction. Three important features of this method are: (1) No uncharged particles are levitated to the workpiece, thereby eliminating the need for recirculating uncharged powder. (2) The method is capable of producing high throughput of charged particles. (3) The method is capable of producing powder with a controlled charge level.

Abstract: A method and system are provided for dispensing only that amount of coating material which is required for coating a series of one or more articles to be coated by the coating material. The method and system include the step of, and apparatus for, feeding that amount of coating material to an intermediate container. The intermediate container receives the coating material from a color changer. The connection between color changer and intermediate container is so designed that no electrical current flow exists between these two components, even when using electrically conducting coating material. The coating material is electrostatically charged at an atomizer downstream from the intermediate container during a spray operation.

Abstract: Method and apparatus are provided for electrostatically spray coating an article in a coating zone with a liquid coating material, such as paint, wherein air is supplied to the spray head of an air spray gun at an atomizing air flow rate in excess of 5 CFM and at a delivery pressure of less than 15 psi to atomize the liquid coating material. At this combination of relatively low pressure and relatively high volume of air the transfer efficiency is substantially higher than for conventional air spray guns. A turbine unit filters and heats the air so that the air has a temperature in excess of 70.degree. F. at the spray head. An elongated conductive rod is reciprocably supported within a nozzle of the spray head to create an electrical charge differential between the atomized liquid coating material and the article in the coating zone when charged by a high voltage source. Preferably, the rod is positioned within a liquid discharge orifice of the nozzle to alternatively open and close the nozzle.

Abstract: An electrostatic coating apparatus is described comprising an applicator, means for supplying liquid to the applicator at a controlled rate, means for establishing an electrostatic field between the applicator and a target substrate to be coated and control means providing an output signal to the liquid supply means for setting the rate at which liquid is supplied to the applicator, the said control means also providing an output signal to the field establishing means which, in operation, sets the magnitude of the applied field, the said output signals being such that the applied field is varied in accordance with any change in the rate of supply of liquid to the applicator.

Abstract: A method of and apparatus for the electrostatic application of a coating material on a product of either electrically conducting or non-conducting material. The product is caused to descend from a hopper (10) in free fall in the form of spaced curtains (28, 30) across two streams (40, 42) of electrostatically charged coating material directed laterally of the curtains from opposite sides thereof. The rate of flow and spacing of the curtains (28, 30) is adjustable (32, 14, 16, 18, 20, 22, 26) as required depending upon the nature of the product and the properties of the coating material. Charges of opposite polarity are applied respectively to the two streams with the result that an electrostatic charge opposite to that of a stream is imparted to that side of each of the two curtains towards which the stream is directed causing attraction between the coating material and the product. The uniformity of the applied coating is much improved as compared with conventional techniques.

Abstract: A method of and apparatus for the electrostatic coating of poorly or non-conductive materials such as pellets seeds and powders, in which the product material is set in motion, preferably turbulent or agitating motion relative to at least one electrostatic coating material spraying device which is directed toward the moving product and has applied thereto a high potential difference whereby the coating material is given an electrostatic charge and an electrostatic charge of opposite polarity is induced on the product causing electrostatic attraction between the coating material and the product. The invention is applicable both to continous and batch production of coated material and preferably involves moving the product past the or each spraying device in a plurality of spraying passes. Charged atomised liquid and diffused powder may be sprayed onto the product either in sequence or at the same time.

Abstract: There is described a method for lining the one surface from a base with a continuous granulate layer, which comprises relieving the granulates from foreign materials, raising said granulates to a higher level than said base, spreading said granulates to form said layer, coating the granulates during the fall thereof with a material causing same to adhere to said base, moving the fall location relative to said base along a direction in parallel relationship with the one base side, at a pre-determined speed, and letting said material coating the granulates laid down on the base, harden.

Abstract: The present invention relates to a powder distributor for electrostatic painting provided with reciprocating vertical movement, wherein the powder in mixture with air reaches the center of a sectional element, for example a disk, which disperses it evenly over its perimetral rim.The distributor comprises a reservoir divided into two chambers by an intermediate porous septum, a first, upper chamber into which a first, powder-in-air suspension feed circuit debouches, and a second, lower chamber into which a second, compressed air feed conduit debouches. Provision can also be made for a third conduit, for compressed air feed, the compressed air being in such case discharged parallel to the direction of discharge of the powder suspension.

Abstract: A system for detecting fire in a powder spray booth having a spray gun for depositing powder onto products moving through the booth includes a switch mounted to the spray gun which is operatively connected to a control system which operates the booth and controls the supply of powder to the spray guns. A spring biases the switch toward an open, operating position in which a signal is sent to the control system to shut down the booth operation and powder supply. Under normal operating conditions, the spring force is overcome by a switch closure mechanism which comprises a fixed rod, and a movable rod mounted to the switch which is pulled toward the fixed rod to close the switch by a burnable filament extending between the rods and positioned in the path of the powder discharged from the spray gun. If a fire starts in the booth, the burnable filament is immediately destroyed and releases the movable rod so that the spring is permitted to move the switch to the open position.

Abstract: An electrode arrangement for a coating installation which functions with the aid of an electric field. The electrode arrangement includes a pair of electrodes for creating an electrostatic field with at least one of the electrodes being fashioned with a sharp edge or tip. The electrode is disposed in a conduit and excess pressure or a vacuum is applied to the conduit with respect to the pressure in the coating chamber of the coating installation in an area of the electrode so that the coating medium is either prevented from coming into contact with the electrode or is suctioned off through the conduit system. By virtue of the provision of the suction removal means for the excess coating medium, the conduit system can be placed in direct communication with the ambient pressure. Additionally, the electrode may be arranged in a vacuum zone of the coating chamber.

Abstract: The inside of a sleeve is positioned over a nozzle having an elongated groove opening immediately at the region of the sleeve to be striped. The sleeve surrounding the nozzle is given a predetermined potential level. A stream of particles is introduced into at least one end of the groove in a direction at least generally parallel to the groove and to the region to be striped. The particles are charged relative to the potential level of the sleeve such that the particles are attracted to the sleeve. A stream of air is also introduced under pressure into the opposite end of the groove in generally the opposite direction. The countercurrent thus produced deflects the stream of powder so it projects generally radially from the nozzle groove, thickly coating the strip region at the seam. The region is the seam of the sleeve which is to be made into a three-part can, in which case the groove is longer than the sleeve.

Abstract: A portable powder spray apparatus for use in combination with a floor supported chain-on-edge conveyor. The apparatus includes a powder spray booth, a fan plenum and a filter module, all of which are mounted upon rollers so that the assembled apparatus may be rolled on or off line relative to a horizontal span of the conveyor.

Abstract: An apparatus and method is detailed for the application of non-conductive material, generally of a powder or fine fiber form from bulk storage onto a conductive filament or plurality of filaments. A series of vibrating troughs are used to store, convey, unpack and load particulate material at a controllable rate into a gas stream traversing a converging-diverging nozzle. High aerodynamic shear in the nozzle reduces the material's size. Divergent nozzle exit geometry slows the material to speeds where electrostatic forces can predominate, as the material is injected upwardly into a chamber fitted with a cascade of conical forms. Each cone is electrified about its circumference in one or more locations, with respect to a centrally located upward moving filament. Conventional electrostatic charging and deposition on the filament is augmented by the convergent geometry of the cones. Excess material falls on the outside of the cones, and eventually downward to a recovery area.

Abstract: A robot painting system for electrostatically painting an automobile body that includes a paint module adapted to maintain the automobile body in a stationary position relative to at least two painting robots, each of which carries a rotary bell-type atomizing device and provides programmed movement thereof about five control axes at a speed which prevents the cone-shaped pattern of atomized paint particles from being distorted due to any gyroscopic effect developed by the atomizing device as it is moved about the control axes.

Abstract: A spray coating apparatus for spraying paint on a vertically moving web is designed to provide an overspray area on each side of the web. In order to remove the oversprayed paint, a pair of liquid film forming boards are located on both sides of the web. Each liquid film forming board is provided with a cleaning liquid supply device along the top edge thereof and a plurality of parallel vertically extending protrusions thereon for forming a downwardly flowing continuous liquid film for removing the oversprayed paint.

Abstract: A plastics material covered metal electrode maintains an electrostatic field dissipating the particles of fine dry powdered dielectric material such as flour or starch to create a cloud or dry mist of the powder in the path of freshly inked sheets as they are discharged from a printing press to prevent smudging of the ink and sticking together of the successive sheets as they are stacked. The electrostatic field is formed across the path of the powder as it is discharged from a supply trough by energizing the electrode with a high voltage current. The plastic covered electrode replaces heretofore required neon gas filled glass tubes which are fragile and burn out. The preferred plastic covering for the electrode is a thermoplastic polyetherimide resin marketed under the name of "Ultem" by General Electric Company of Pittsfield, Mass.

Abstract: In the electrostatic application of a coating material on to a product to be coated, the product leaves a supply hopper over a tube enlargement and falls freely in a chamber in the form of a tubular curtain. The tubular curtain falls around a central, elongate, vertical corona discharge electrode so that a high voltage electrostatic charge of one sign is applied to the falling curtain of the product. Coating material is sprayed on to the product by atomizers in the chamber. A high voltage electrostatic charge of opposite sign is applied to the coating material by way of the atomizers.

Abstract: In this process comprising fluidizing the enamel powder in a fluidization vessel by blowing air in the bottom of the latter, steam is also introduced in the vessel in the course of the fluidization. The relative humidity is adjusted in the vessel to a value between about 15 and 45% in respect of a temperature in the vessel of between about 20.degree. and 30.degree. C. A steam boiler (12) is connected to the fluidization vessel (1) for this purpose.

Abstract: The electrogasdynamic coating system includes an electrogasdynamic gun for charging material particles indirectly. The gun has a gas inlet which receives from a gas source a pressurized gas in which an condensable vapor is entrained. Corona and attractor electrodes are disposed in communication with the gas inlet for ionizing the ionizable vapor. A dielectric tube extends from the electrodes downstream to a mixing chamber. A first fluid material inlet is connected with a first source of powder or liquid material and a second fluid material inlet is connected with a second source of powder or liquid material. The first and second fluid material inlets are connected with the mixing chamber such that particles of the first and second fluid materials are mixed with the gas and vapor. The vapor condenses and coats the particles during mixing causing them to become charged. In use, a condensable vapor is entrained into a gas flow, the gas flow is passed across corona and attractor electrodes to ionize the vapor.

Abstract: The electrogasdynamic coating system includes an electrogasdynamic gun for charging material particles indirectly. The gun has a gas inlet which receives from a gas source a pressurized gas in which an condensable vapor is entrained. Corona and attractor electrodes are disposed in communication with the gas inlet for ionizing the ionizable vapor. A dielectric tube extends from the electrodes downstream to a mixing chamber. A first fluid material inlet is connected with a first source of powder or liquid material and a second fluid material inlet is connected with a second source of powder or liquid material. The first and second fluid material inlets are connected with the mixing chamber such that particles of the first and second fluid materials are mixed with the gas and vapor. The vapor condenses and coats the particles during mixing causing them to become charged. In use, a condensable vapor is entrained into a gas flow, the gas flow is passed across corona and attractor electrodes to ionize the vapor.

Abstract: Process for electrostatically coating objects with a fluid, for instance liquid paint, by applying a high voltage to a spray bell and by feeding the fluid to a revolving, driven spray bell. The flow-rate of the fluid supplied to the center of the spray bell is decelerated nearly to zero when it enters the bell, then the rate of the fluid is increased by being accelerated by the bell to 15,000 to 60,000 rpm, and the fluid thereupon is centrifuged off the spray rim of the bell and is guided to the object to be coated.

Abstract: A workpiece which may be made of a highly electrically insulating material is held in a spaced opposing relationship with respect to a silent discharge plate electrode to which an a.c. voltage is applied. A d.c. voltage is applied across the workpiece and the silent discharge plate electrode to form a driving electric field therebetween. Powder particles suspended in air are charged in the same polarity as that of the silent discharge plate electrode and then injected into the region between the silent discharge plate electrode and the workpiece where the electric field drives the charged particles toward the workpiece to coat it. The a.c. voltage is sufficient to repel the electrode surface confronting the workpiece and to maintain the silent discharge at a reduced level and effectively precluding deposit of powder particles on the mentioned surface. An apparatus for the electrostatic coating is also disclosed.

Abstract: An apparatus is disclosed for the automatic coating of articles. The apparatus has a spray device controlled by a programmed control device. A transport device transports the articles along a predetermined path to a coating position and then away therefrom after coating. A sensor monitors the position of the article and generates signals representative thereof, preferably generating one signal each time the article moves a predetermined distance (e.g. 2 cm.) along the path. A second sensor generates additional signals to the control device when an article passes a predetermined point, also indicating which of several types of articles has been detected. The control device controls the spraying process responsive to these signals. If desired, portions of the article that are moved sequentially into the coating position can be sprayed in different manners, e.g. with the spray devices positioned or oriented differently, or using different coating materials, etc. The control device is preferably reprogrammable.

Abstract: A fire-extinguishant system includes a source of extinguishant, such as carbon dioxide, a fusible length of plastic tubing, such as one-half-inch-outside-diameter polyethylene tubing, with the end closed, and a conduit and valve system for connecting the extinguishant source to the fusible tubing. The valving system pressurizes the fusible tubing at a low pressure, and this low-pressure signal is coupled to a pilot input port in the valve system. When this low-pressure pilot signal is interrupted, the piloted valve switches to supply extinguishant at full pressure through the fusible tubing. If the fusible tubing has been melted, such as by a fire, the extinguishant exits through the melted portion to extinguish the fire. The low-pressure pilot signal can, however, be interrupted manually by the valve system. In this case, the full-pressure extinguishant supply to the fusible tube ruptures the tube and releases extinguishant. This provides a manual extinguishant control for the system.

Abstract: Migration imaging apparatus of the kind using a photoelectrophoretic dispersion and having an electrode moveable along an endless operative path past dispersion application and imaging zones features improved dispersion applicator structure comprising a flat-spray, atomizing nozzle adapted to form a uniform layer of dispersion on the electrode without imparting velocity perturbations to the moving electrode.

Abstract: Apparatus for electrostatically coating an elongated object of indefinite length which is aligned with the straight line path of the elongated object in a continuous manufacturing and finishing process. Electrostatic applicators are mounted to direct the coating into a substantially closed chamber at a portion of the elongated object passing therethrough. To substantially eliminate the explosive hazard occasioned by the use of an organic solvent-based coating material in the presence of electrical equipment, a combustibly inert atmosphere is maintained in the chamber and in an exhaust system leading therefrom. To maintain the electrostatic field, the coating chamber and associated coating equipment must be electrically isolated from ground.

Abstract: A device for the electrostatic application of particles entrained in a stream of gas to a non-conductive, flat substrate, typically a web or sheets of paper. The particles are electrically neutral in the stream. A charging electrode is located below the substrate in the area where the gas stream impinges on the substrate. The substrate is advancing lengthwise, and a counterelectrode is located below the substrate in the direction of advance from the charging electrode. Preferably the direction and velocity of the gas stream near the substrate and direction and velocity of the substrate itself are approximately equal. Also in the preferred form, a grounded collecting pan is located beneath the electrodes.

Abstract: A method and apparatus for depositing flock wherein flock fibers are fed at a controlled rate from a storage hopper through a screen into a propelling air stream. The air stream carries the fibers in a rotationally stabilized flow to an applicator gun where they may be electrostatically charged, and they are propelled by the air stream and deposited on the adhesively coated surface to be coated.

Abstract: Lubricating material is applied to a fast moving strip within a vertical deposition chamber having smooth side walls and a roof slanted at an acute angle with respect to the side walls on each side of the chamber at its top. A plurality of sources of lubricating particles are spaced in each side of the deposition chamber intermediate its top and bottom. Each of the sources includes a horizontal chamber outside of the deposition chamber and opens into the deposition chamber. Each of the sources have a plurality of compressed air atomizers supplied from a supply of lubricating material in said horizontal chamber and are adapted to remove the larger particles of lubricating material from said spray and to urge the remaining smaller particles into the deposition chamber by the residual flow of compressed air from said atomizers. Lubricating particles flow slowly and without significant momentum into the deposition chamber.

Abstract: An elongate electrical conductor is continuously coated with electrostatically charged powder by passing the conductor upwardly through a tube into the upper portion of a container having a charged fluidized bed of the powder in a lower portion thereof. The tube extends upwardly through the bed and the tube height is adjusted relative to the upper surface of the bed to control the thickness of the powder coating. An array of electrodes having associated switches permits application of uniform coatings to conductors having a variety of shapes. Two or more conductors may be uniformly coated from the same fluidized bed in a container having a baffle which divides the upper portion into two or more compartments and spaced apart tubes extend upwardly into the different compartments.

Abstract: This invention relates to a continuous process for electrostatically coating a substantially axially symmetrical object with pulverized material, characterized by conveying said object by means of a conveyor-type holding device into an electrostatic coating chamber equipped with silent discharge plate electrodes on both sides of the chamber walls: feeding electrically charged pulverized material into said chamber: electrostatically coating said object with said pulverized material by the action of silent discharge from said electrodes: and removing surplus pulverized material from the specific parts of said object by suction.

Abstract: Forming a colored shade band on an elongated area of a flexible sheet of interlayer material comprising applying a dye composition by electrostatic spraying against a portion of a surface of a flexible sheet of non-conductive interlayer material such as polyurethane or plasticized polyvinyl butyral. A novel grounded shielding structure of electroconductive material comprises a primary shield located in close proximity to the upper surface of a workpiece to be partially coated. A preferred embodiment comprises primary and secondary shields with an optional manifold between the shields to ensure superior control of a pattern of graded intensity along the transverse dimension of an elongated area to be coated. One or both shields may be heated to avoid the deposit of spray particles that cause optical defects. The workpiece so coated is useful as an interlayer in shaded, bent laminated safety glass windshields.

Abstract: The invention relates to an improvement in an electrostatic coating apparatus comprising a booth, air flow means, conveyor means and a powder spray gun, wherein the improvement comprises an endless conveyor belt and gaseous projection means for redirecting particles of coating material falling toward the floor to the articles to be coated and electrostatic means for recharging the particles.

Abstract: The specification discloses a means and method for electrostatic coating of objects with synthetic resinous powdered material in which increased electrostatic charges are placed upon the powdered coating material before they are moved through the vicinity of the article to be coated by subjecting them to acceleration in a closed circuitous path from which they are tapped for movement to the coating area.

Abstract: A method and apparatus for coating the inside of tubular members, more specifically can bodies, which are open at opposite ends. The apparatus includes a supply tube and a return tube which are spaced apart to have received therebetween the tubular member to be coated. In each of the supply tube and the return tube there is positioned a corona electrode, the corona electrodes being in alignment wherein powder supplied to the interior of the tubular member is both initially charged as it passes through the supply tube and is further charged within the tubular member by an electrical field which exists between the two corona electrodes and the tubular member.

Abstract: An electrostatic hand-held coating-dispensing apparatus includes a first pulley, a second pulley, and a continuous belt trained about the first and second pulleys. The first and second pulleys are supported and retained in spaced apart relation to maintain tension on the belt in a supporting housing. A first brush is provided adjacent the belt where the belt is trained about the first pulley. A second brush is provided adjacent the belt where the belt is trained about the second pulley. A curved conducting surface is also supported by the housing. The second brush is connected to the conducting surface. A small alternating current electric motor is provided for turning the first pulley. A container or canister is provided for the coating material. The canister is snugly received in the supporting housing in a position adjacent the conducting surface. The canister includes an end for transferring electrostatic potential from the curved surface to the coating material therein.

Abstract: A novel metallic squeeze-out tube suitable for packing paste-like foods whose flavor is regarded as important or the like is described herein, in which a resin powder layer is formed on its inner surface and on the outer surface of its neck portion by electrostatic painting and thereafter it is finished by baking, whereby a resin coating film that is free from pin holes and has a strong corrosion resistance can be formed.

Abstract: A flocking system including a cabinet supporting a substrate to be flocked and a flock tray, means for raising and lowering the flock tray into and out of contact with the substrate (such as a garment), and means for sealing the moving flock tray to the cabinet to prevent flock from getting into the cabinet to prevent contamination of the mechanics of the internal portion of the cabinet by flock. The flock tray includes a slowly rotating rotor for keeping the flock agitated, a telescoping shaft connecting the rotor to the motor, a flock tray holder for maintaining the seal with the cabinet, and a flock tray cover with one or more flocking masks with various size openings.

Abstract: Process for the transformation of comminuted and modified cellulose ether swellable with water, into a material that may easily be further processed and may thus be used without difficulty in particular in the production of hygienic pads, napkins, bandages, tampons, wrapping papers, insulating material, household papers and similar articles. In said process the modified cellulose ether is attached by electrostatic flocking to at least one surface of a web-shaped hydrophilic support that has been wetted with water and the support is dried.

Abstract: A gun for tribo charging powder has a barrel body with a bore having an opening at one end. A venturi forming tube is contained in the barrel bore and a supply of powder enters the barrel through a bore of the venturi forming tube, which is in alignment with the bore of the barrel, creating an obstruction free passageway for the powder. A supply of pressurized propellant gas enters the barrel bore through an area between the outer venturi forming tube wall and the inner barrel wall and is the power source for charging the powder. Modifications for increasing the charge imparted to the powder include an insert in the venturi forming tube bore for forcing the powder to travel closer to the barrel wall upon exiting the venturi forming tube bore, and a system of holes through the venturi forming tube wall for imparting swirling motion to the powder in the venturi forming tube bore.

Abstract: An electrostatic fluidized bed apparatus having a housing supporting a removable container defining a fluidizing bed and a plenum chamber and having a porous insulated partition therebetween containing an electrode. When the container is positioned in the housing of the plenum chamber is automatically connected to an air pressure source and the electrode is automatically connected to a high voltage electrical power source and vibration system contained within the housing. The container may be used as a powder storage bin when removed from the housing.

Abstract: A safety power supply system for electrostatic spray coating utilized high frequency (audio or radio frequencies) rectified DC pulses to provide the high voltage between an electrode on a spray gun and work to be coated. A high resistance direct electrical path to ground is provided for all parts of a coating system charged to high voltage during coating operations including highly conductive coating materials. For manual spray guns small electrodes or the atomizing edge of a coating material provides the electrode making it virtually impossible for an operator to come in contact with high voltage charged parts before a charge is substantially bled to ground.

Abstract: An apparatus for collecting powder exhausted from an electrostatic fluidized bed coater, in which exhaust air passes from the cloud chamber of the coater into an inner exhaust chamber and then passes through a porous plate to an outer exhaust chamber, the powder carried by the exhaust air being stopped by the porous plate and thereafter collected from the inner chamber.

Abstract: Powder to be deposited electrostatically by spraying from a nozzle is charged tribo-electrically. The powder is admitted at a controlled rate to a housing through which an air stream is caused to flow and becomes charged by frictional impact with the surface of a rotor which intercepts the air stream. Charged powder suspended in the air stream passes through a conduit to the nozzle at which a baffle is located to cause the powder to be sprayed in a predetermined distribution.

Abstract: An electrostatic fluidized bed coating unit is disclosed. The coating unit comprises a plenum chamber with means for ingress of a gas under a greater than atmospheric pressure, a porous plate located on top of the plenum chamber and extending to the limits of the containing walls of the plenum chamber, containing walls for powder immediately above the porous plate and forming essentially a continuation of the plenum chamber walls, a coating chamber secured to such powder containing walls, and an exhaust system for effecting a uniform fluidizing gas removal from an area essentially directly above the porous plate.

Abstract: An apparatus for the electrostatic application of a coating material in the form of a liquid to articles or the like comprising a nozzle at the region of which there are provided at least two electrodes at which there is applied high-voltage of the same polarity but of different magnitude. The electrical field between the electrodes covers the nozzle opening in the form of a transverse field.

Abstract: A continuous powder feed system for maintaining an essentially uniform powder cloud above an electrostatic fluidized bed coating unit is disclosed. The continuous powder feed system comprises a powder container and discharger for continuously feeding essentially non agglomerated powder into the coating bed of the electrostatic fluidized bed coating unit, powder retaining walls for containing the bed of such coating unit during fluidization, at least one powder retaining wall having a height such as to determine the powder level in the coating bed and permit overflow of excess powder from the coating bed, and a powder collection system for retrieving the overflowing powder from the coating bed.

Abstract: In this arrangement a circuit is provided for generating deflection voltages for the coloring material marking the insulation of electrical conductors as the electrical conductors are extruded which compensate for distortions in the shape of color ring insulation markings when large ring spaces or high conductor extrusion speeds are employed. Two spaced spray nozzles are used to provide two streams of color material. These nozzles are disposed on opposite sides of the extruded electrical conductor, each of the spray nozzles provide one half of the color rings. The deflection voltage consists of a rectangular waveform with a semicircular top portion. A high resistance potentiometer is connected between the two spray nozzles with the wiper of the potentiometer connected to a high DC voltage source. Adjustment of the wiper renders the amplitudes of the two streams of color material equal.

Abstract: A straining filter which has an opening at the highest point of the filter dome is inserted in the pipe which supplies the spray nozzles and is further connected to the opening of an additional pipe. Spray nozzles acted on by an electrical field supply colored marking rings to a cable or wire. The material to be sprayed is held in the storage tank and is transferred by a gear pump through a buffer vessel and into a pipe. Inserted in the pipe is a double walled straining filter whose outlet is connected to a pipe running to the spray nozzles, with a valve and a pressure gauge inserted between the straining filter and each spray nozzle. Any gas bubbles introduced into the straining filter with the color material gather at the highest point of the filter dome and are carried away therefrom.

Abstract: This apparatus comprises in combination means for processing the pulverulent product, which subject this product to a sudden pressure drop and deliver a pulverulent fluid formed by solid particles of the product suspended in a carrying gas, a storage chamber communicating with said processing means, spraying means connected to said chamber by a pipe and means controlling the flow of pulverulent fluid through said pipe.