Abstract: A self-clean oven having means for passing cooling air over the heated walls of the oven and further having means for supplying combustion air by normal inspiration to the oven burners independently of the flow of cooling air, and having still further means for mixing hot combustion products exhausted from the interior of the oven with exhausted cooling air to prevent passage of excessively hot air into the atmosphere.

Abstract: A method and apparatus for providing high reliability ultrasonic bonds by monitoring the force required to separate the bonding tool from the wire after the bonding operation. This force which is required to break an incidental bond between the tool and the wire is related to the quality of the primary bond of the wire to a conductor terminal. The output of a transducer is proportional to the force and it may be coupled to a visual display, alarm, or computer for trend analysis.

Abstract: A convection oven in which vapor is circulated through the oven by a pair of counter rotating blowers positioned in the rear of the oven which draw vapor from the oven along with combustion products from a multi-section ribbon burner which has a secondary air passage between the sections and which is positioned below the oven rear wall vapor outlet region and blow the combined vapor and combustion products into the oven adjacent the top surface. The blowers generate slight negative pressure in the combustion plenum by blowing a small portion of the output of the blowers out an output vent to control the amounts of primary and secondary air supplied to the burner system.

Abstract: A door seal for a microwave oven wherein the distance between the choking structure in the door and a substantially planar surface around the periphery of the access opening can be independently adjusted at a plurality of locations around the periphery. The door which is flexible is connected to a rigid door support structure by a plurality of bolts around the periphery of the door. The distance between the door and its support structure can be independently varied at each bolt to conform the contour of the door to the substantially planar surface against which it closes. Accordingly, the choke gap can be optimized around the periphery of the door. The support structure is movable in a vertical plane to open and close the door.

Abstract: A filter for suppressing backward wave energy modes propagating along a slow-wave structure. The filter is frequency responsive and comprises a wall having coupling apertures and, in one embodiment, a series of waveguide sections which are joined to the coupling apertures and alternate sections are terminated in matched loads. The apertured wall encloses the slow-wave structure and the apertures are arranged relative to periodic elements of the slow-wave structure such that a forward wave can propagate with substantially no interaction with the filter while the energy in a backward wave is dissipated in the matched loads. The filter is particularly adapted for absorbing backward waves in a travelling wave tube operating at high power and an octave bandwidth.

Abstract: A microwave heating appliance having a metallic member supporting a body comprising ferrite bonded to an outer surface of the metallic member with a grooved inner surface of the metallic member contacting a food body to be heated by thermal energy generated from microwave energy absorbed by the ferrite body and transferred through the metallic member to the food body. An additional metallic member forms a container for the food body, and adjacent peripheral areas of the two metallic members provide substantial microwave sealing between the two metallic members thereby substantially shielding the food body from the microwave energy when the appliance is placed in a microwave oven. Upper and lower surfaces of the interior of the appliance contain grooves to form corrugated surfaces which contact the food body and which permit juices produced by heating the food body to flow away from regions of contact between the corrugated surfaces and the food body.

Abstract: A combination microwave and electrically heated oven having a door with a high temperature seal which inhibits the escape of hot gases around the periphery of the door and which is isolated from the major portion of the electric fields of the microwave energy entering the space between the door and the oven aperture walls by a slotted choke microwave seal so that the vapor seal may be formed which high microwave energy absorption characteristics without either reducing the intensity of microwave energy in the oven or causing substantial heating of the vapor seal by microwave energy.

Abstract: A microwave oven feed system having the output probe of the magnetron inserted directly into the microwave enclosure. A rotating feed structure positioned within the enclosure couples the microwave energy from the probe into a directive radiation pattern towards the food. The feed structure may be located in a well extending from the enclosure and separated from the processing cavity by a layer of microwave transparent material, the functions of the layer being to provide thermal isolation and to provide a protective covering for the feed structure. A microwave choke around the periphery of the well prevents leakage of microwave energy from the enclosure. The choke may be elevated from the floor of the cavity to prevent food drippings and spilled soups from running into the feed structure well.

Abstract: A method of forging spinel into complex shapes in which a spinel plate is placed in a mold while the spinel plate is heated, in an atmosphere of helium, to a temperature below its melting point and above its solid two phases transition point that allows plastic deformation to take place. Forging stresses well above the yield point of the spinel are applied to the plate by the mold to reduce the forging time.

Abstract: A microwave heating system having a rotary multiport microwave radiator positioned in a cavity and having radiating ports at different distances from the axis of rotation which direct overlapping radiation patterns at a body to be heated. A combination heater may be used having a resistive heater positioned in regions around the outside of the rotary structure to supply heat to the body.

Abstract: A bright display radar system having anticollision capabilities in which received signals are digitized at a rate determined by a radar range setting and displayed at a constant relatively slow rate independent of the range setting. A computer based anticollision unit operates in response to the relatively slow digitized received signals so that targets may be tracked equally well at short and long ranges. Two sets of operator actuable switches are provided for controlling the anticollision unit. A first set of switches is provided which correspond directly to the most commonly used computer operating functions. The second includes an alphanumeric keyboard which may be used to actuate subroutines stored in a physically separate read-only memory which operates only in response to the alphanumeric keyboard.

Abstract: A microwave heating system having a combination rotary blower and multiport microwave radiator positioned in a cavity and having radiating ports at different distances from the axis of rotation which direct overlapping radiation patterns at a body to be heated. A combination heater may be used having a resistive heater positioned in regions around the outside of the rotary structure to supply heat to the body.

Abstract: A gas-fueled oven which is capable of safely assuming high temperatures such as occur during pyrolytic self-clean cycles and which employs a single multi-purpose fan for directing cool air flows over wall surfaces, for providing aspiration and temperature dilution of hot flue products, and for providing combustion air for a power broiler burner.

Abstract: A laser gyroscope having a multi-frequency ring laser resonator containing a gas laser energized by electric discharge through a gaseous laser medium from two anodes to a common cathode positioned outside the lasing passage and communicating therewith through a narrow bore having a nonuniform constant magnetic field applied to the gaseous discharge in said bore to suppress high frequency gas discharge oscillations in the laser.

Abstract: A method for simultaneously soldering the two solder covered ends of an electronic chip component to respective conductor pads. Pulsed coherent laser radiation having a predetermined energy profile is separated into two spacially separate beams and they are respectively directed toward the opposing ends of the chip to reflow the solder.

Abstract: A scanning system combining active and passive detection of radiation from targets. In the active mode, a laser beam is scanned with a rotating wedge in a downward looking Palmer pattern, a portion of the beam is reflected from targets, and coherent detection is performed on the returned signals. Means is disclosed for automatically compensating for misalignment between the signal return beam and local reference beam upon the coherent detector. In the passive mode, infrared radiation inherently emitted by targets is also detected.

Abstract: A method and apparatus for fracturing and/or heating subsurface formations wherein an alternating current electric field is produced in the frequency range between 100 kilohertz and 100 meghertz between electrodes spaced apart in the formation and a radio frequency generator supplying a voltage between said lines with suitable loading structures tuned to the frequency of the generator to resonate the electrodes as a parallel wire transmission line which is terminated in an open circuit and produces a standing wave having a voltage node at the end of the line.

Abstract: A transducer for a SAW device having withdrawal weighting combined with series sections weighting to achieve a desired frequency response. Withdrawal weighting is employed where the impulse response can be adequately approximated by a withdrawal pattern with series sections electrodes being used to provide the additional weighting required. Additionally, electrodes using a different number of series sections are separated by a gap a few wavelengths wide in order to avoid sharp discontinuities.

Abstract: A bus arbitration method and apparatus for determining which of a plurality of devices desiring access to a common bus will gain access to the bus when it becomes available. Using the change of state of a common BUSY line to synchronize the simultaneous initiation of the arbitration process in each competing device, each device outputs a unique signal to a common arbitration line or lines. Each device monitors the composite signal on the arbitration line or lines and determines its priority relative to other devices. The device with the highest priority gains access to the bus and outputs a signal to the BUSY line until the bus is available for another arbitration.

Abstract: A utensil for steam cooking in a microwave oven. The bottom portion of the utensil is a microwave transparent dish in which water is placed. A metal pan having a plurality of holes in the bottom is supported in the dish in a fixed horizontal alignment with the bottom spaced above the water level. A tray for holding food is positioned in the pan; the tray may be inverted to provide a second support surface configuration. A metallic cover is supported by the dish and is thereby secured in a spaced overlap alignment with the pan to substantially provide a microwave choke therebetween. The water in the dish is heated by microwave energy to provide steam which passes through the holes into the cooking region. Substantially all of the available microwave energy is absorbed by the water as the food is shielded by the combination of the pan, cover, and the choke therebetween.