Abstract: A fired, electrically semi-conducting ceramic body is disclosed. The body consists essentially of silicon carbide particles having a median particle size from about 3 to about 25 microns dispersed in a bonding matrix. The silicon carbide particles constitute from about 50 to about 70 percent of the body. The body has an "apparent porosity" as subsequently defined herein from 20 to 40. The production of such a body from a batch composed of silicon carbide, alumina, silica and at least one oxide, carbonate or hydroxide of calcium, magnesium, barium or strontium is also disclosed. The batch is milled and pressed into a shape, and the resulting shape is then fired in an inert gas atmosphere to a temperature from about 2,300.degree. to 2,800.degree. F. for a time sufficiently long to produce a semi-conductor body having the requisite apparent porosity of from 20 to 40 percent.

Abstract: A high-silica ceramic glaze, having a low coefficient of thermal expansion, suitable for application to alumina bodies, is disclosed. The glaze consists essentially, by weight percent, of 48 to 54 percent SiO.sub.2, from 7 to 11 percent Al.sub.2 O.sub.3, from 161/2 to 20 percent B.sub.2 O.sub.3, from 11 to 14 percent BaO, from 2 to 3 percent CaO, from 2 to 21/2 percent ZnO, from 41/4 to 51/4 percent Na.sub.2 O, and from 0.4 to 1 percent K.sub.2 O. Li.sub.2 O and MgO to the extent of up to about 1/4 percent and 1 percent, respectively, can also be tolerated, as can minor amounts of other impurities.

Abstract: An improved ultrasonic nebulizer for administering a medicament aerosol to a patient. Output from an oscillator is connected through a series inductor to a transducer adjacent a reservoir which generates aerosol from the medicament. The inductor is tuned for series resonance with the bulk capacitance of the transducer. An impedance change in the transducer when liquid is removed or consumed from the reservoir reduces the power delivered to the transducer and prevents transducer damage.

Abstract: A high-silica ceramic glaze, having a low coefficient of thermal expansion, suitable for application to alumina bodies, is disclosed. The glaze comprises, by weight percent, about 50 percent SiO.sub.2, from 5 to 8 percent Al.sub.2 O.sub.3, from 6 to 12 percent B.sub.2 O.sub.3, from 2 to 15 percent BaO, from 5 to 8 percent SrO, from 4 to 6 percent CaO, from 2 to 8 percent MgO, from 1 to 2 percent ZnO, and about 5 percent total of Na.sub.2 O, K.sub.2 O, Li.sub.2 O, and minor impurities.

Abstract: The present invention provides a novel cellular ceramic catalyst support. The support consists of a random-fiber ceramic framework having a high surface area. The support is fabricated by flocking an organic sponge with wood or textile fibers, and impregnating the flocked sponge with a high alumina slurry containing a silicone resin and a flux. The impregnated organic sponge is sintered at a high temperature to burn out the organic sponge material. A fired high-silica glaze can be applied to the sintered article, followed by a second sintering step. A second glaze containing from 10-25 parts by weight CuO and from 10-25 parts by weight ZrO.sub.2, can be applied, followed by a 2000.degree. F. sintering step. The high temperature causes recrystallization of the CuO onto the surface of the catalyst support thereby increasing the surface area. The glazed surface can be plated with copper or nickel and combinations thereof to function as a reducing unit in a catalytic converter.

Abstract: A spark plug and connector assembly having a spark gap formed from two electrodes which are both electrically isolated from ground. The spark plug includes an insulator mounted in a tubular metal shell having a threaded end for engaging a corresponding opening into a combustion chamber in an internal combustion engine. The two electrodes are mounted within separate parallel bores through the insulator. Each electrode has a tip projecting from the insulator for defining the spark gap. The electrodes also have terminal ends which are recessed within the insulator bores. The electrode terminal ends are centered within and spaced from the walls of the bores. Tubular connectors attached to the ends of two high-voltage ignition cables are received within the insulator bores and slide telescopically onto the electrode terminal ends. The connectors are also recessed within the insulator bores to prevent arcing therebetween.

Abstract: A spark plug having an internal auxiliary spark gap in series with an ignition noise suppressor in a center electrode is disclosed. One side of the series gap is formed by a conductive ball which also supports the suppressor.

Abstract: The present invention relates to a novel aqueous dispersion of a silicone resin and alumina. The dispersion is prepared by mixing 50-90 parts by weight of alumina, 6-45 parts by weight of a phenyl lower alkyl silicone resin and 1/2-6 parts by weight of a flux with from 1/2-7 parts by weight of an alkylolamine detergent in sufficient water to form a dispersion having a viscosity ranging from 300 to 3,000 centipoises.

Abstract: An improved high voltage pulse power supply for a spark plug test fixture. AC line voltage is applied through a voltage step-down transformer, a half wave rectifier and an electronic switch to the primary winding of a conventional ignition coil. During the rise time of positive half cycles, the rectified voltage is applied through the electronic switch to the ignition coil primary. As the positive half cycle begins to fall towards the zero crossover, the electronic switch is opened. The magnetic field collapse in the ignition coil produces a high voltage negative pulse which is applied to a spark plug under test. The peak voltage of the negative pulse is adjusted by controlling the peak current in the ignition coil primary.

Abstract: This invention relates to a fluid actuated paint pump for high pressure airless spray guns and includes a novel unloading system in combination with a self-reversing fluid motor connected to a double-acting pump which supplies paint from a reservoir to an airless spray gun at a pressure which may run as high as 3500 psi.

Abstract: An improved spark plug for use in an internal combustion engine having a capacitive discharge ignition system. The spark plug includes a conventional metal shell supporting an insulator having a center electrode bore extending therethrough. A center electrode mounted in the insulator bore includes an electrode tip which defines a spark gap with a ground electrode. An auxiliary spark gap is formed within the insulator bore immediately above the tip. A low resistance inductive suppressor is mounted above the auxiliary spark gap and has an end attached to a terminal for connection to the capacitive discharge ignition system.

Abstract: An improved resistor element especially suitable for use in spark plugs is disclosed. The resistor element is prepared from a stannic oxide-barium, calcium or strontium borate composition doped with from 1 to 18 percent tantalum pentoxide or 1/2 to 5 percent niobium pentoxide based on the total batch weight. A method for producing the element is also disclosed.

Abstract: An improved semiconductor and semiconductor coating for alumina electrical insulating devices is disclosed. The semiconductor is prepared by applying a layer of a mixture of monoxide and sesquioxide combination to an alumina body and firing at a temperature of 2300.degree. or above thereby forming a stable spinel. The electrically-conductive monoxide can be FeO, Cu.sub.2 O, CuO, NiO, CoO or MnO. The sesquioxide can be Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, Ga.sub.2 O.sub.3, Ca.sub.2 O.sub.3, Mn.sub.2 O.sub.3, Al.sub.2 O.sub.3 or Ti.sub.2 O.sub.3.

Abstract: A spill preventing diaphragm attachment for a paint spray gun paint cup as shown. The diaphragm is engaged around the mouth of the paint cup and forms, with the undersurface of the paint cup lid, a chamber above the paint in the cup that is deeper at one side than the other. At the deep side, oriented 180.degree. away from the vent opening in the lid is a vent opening in the diaphragm. Any paint that might flow through the diaphragm vent opening as a result of tipping the spray gun drains back into the cup as soon as the gun is righted. The diaphragm is readily replaceable without tools.

Abstract: Improved method and apparatus for measuring the effective operating resistance of an unknown resistance element to which repetitive high voltage pulses are normally applied during operation. As each high voltage pulse is applied to the element, the voltage across the element and the current through the element are simultaneously sampled during voltage peak or at any other desired point in each pulse. The voltage and current samples are digitized and used in digitally computing the effective operating resistance of the unknown element. The computed resistance is displayed on a digital indicator.

Abstract: A method for producing a semi-conductor body is disclosed. The batch for the body is silicon carbide and reactive alumina. The batch is first dry ball milled with from 1/2 to 2% fatty acid and pressed into a shape. The shape is then fired either in air below 2300.degree.F. or in an inert gas atmosphere to a temperature from about 2000.degree. to 3000.degree.F., and for a time sufficiently long to produce a semi-conductor body having a specified apparent porosity. An impregnation step is also disclosed to achieve the specified apparent porosity.

Abstract: This invention relates to spark plugs for internal combustion engines and is particularly directed to a center electrode having a sparking tip composed of a precious metal and to the method of making the same. The known advantage of the use of a precious metal electrode is that considerably greater spark plug life is achieved. The invention achieves the advantage while greatly reducing the mass of precious metal employed. A further feature of the invention is the co-planar disposition of the end of the center electrode and its supporting insulator.

Abstract: An improved electrostatic spray gun for the deposition of powdered coating material on a workpiece is disclosed. The spray gun includes a housing having a barrel to which a nozzle is attached for directing the powdered material to the workpiece. A charging electrode, which is connected to a high voltage power supply, is mounted on a diffuser assembly which is clamped between the nozzle and the housing, on which the nozzle is threaded. A regulated gas flow supplied through the housing and the diffuser assembly provides a gas shield around the charging electrode to prevent a buildup of the coating material on the electrode. A novel pneumatic safety interlock continuously monitors the pressure of the gas supplied to the diffuser assembly. The interlock turns off the high voltage power supply and a pump for the coating material in response to a drop in such pressure resulting from a loose nozzle.

Abstract: An improved ceramic article useful after firing as an electrical suppressor element, especially suitable for use in spark plugs, is disclosed. The suppressor element is a copper-aluminum composition modified with a mangesium, calcium, strontium or barium metal compound. The numerical value of the atom ratio of the article,Cu/M+ Alwhere M represents magnesium, calcium, strontium or barium is from 0.5 to 4. The atom ratio of M to Al is from about 0.5:1 to 2.0:1. The temperature coefficient of resistance of the suppressor, defined by ##EQU1## is between about -0.1%/.degree.C and -1.0%/.degree.C.