Abstract: A method for controlling heating and avoiding arcing in microwave food packaging having a conductive material such as a metal foil on the packaging by controlling the cross-sectional shape of the foil to have a predetermined shape at the edge portion of the foil including controlling a wedge angle and a corner radius of the edge of the foil.

Abstract: Apparatus for and method of controlling heating of a foodstuff using microwave energy having a food package with a microwave shielding layer containing a plurality of apertures therein sized to permit entry of both evanescent microwave energy and propagating microwave energy into the interior of the package with the microwave shielding layer being moved outward as the package expands due to generation of water vapor such that an interior volume of the package is subsequently protected against substantial evanescent microwave irradiation of the foodstuff during completion of the microwave heating cycle using propagating microwave energy to further heat the foodstuff.

Abstract: A food package and method of controlling heating of a foodstuff within the food package using microwave energy wherein the food package has a microwave shielding layer containing a plurality of apertures therein sized to permit penetration of evanescent microwave energy into the interior of the package with the microwave shielding layer being moved outward as the package expands due to generation of water vapor such that an interior volume of the package is subsequently protected against substantial microwave irradiation of the foodstuff upon and beyond completion of the microwave heating cycle.

Abstract: A microwave applicator (10) including a tunable cavity (12) having by an elongated casing formed from a transition section (14) axially secured between upstream and downstream end sections (16) and by first and second end assemblies (28) each axially movable in the elongated casing. A tube assembly (72) passes through and is rotatably supported within tubes (36) of the end assemblies (28) and passes through the elongated casing. Material in the tube assembly (72) in the elongated casing and between the end assemblies (28) are subjected to microwave power introduced into the transition section (14) by a waveguide (110) via an opening 20. The axis of the tube assembly (72) is adjustably offset from that of the elongated casing and the transition section (14) is adjustably fixed at various circumferential positions to superimpose the material bed in the tube assembly (72) with the area of highest field strength.

Abstract: A combined transformer and motor having a continuously energized primary winding producing a continuous output voltage from a transformer winding and a selectively enabled motor shaft rotational output which is selectively actuated by powering a further primary winding.

Abstract: An interlock switch assembly is disclosed having a unitary baseplate with relatively few moving parts and making use of conventional low cost miniature switches, each positively located and retained with respect to the baseplate. First and second actuators convert, respectively, linear motion of first and second operators into rotary motion to actuate the miniature switches. Switch actuation is prevented unless the properly timed motion of both operators is received by the actuators. A third actuator receives the motion of the first operator and actuates a third switch in response thereto. In one embodiment, the third actuator is prevented from actuating the third switch until after actuation of the first and second switches. In one embodiment, a primary interlock switch is the first switch deactuated and is preferably capable of interrupting power to the microwave energy source when the door is opened before the cooking cycle is completed.

Abstract: A method and apparatus for operating a DC motor controller according to a first gain when the armature current of the DC motor is discontinuous, according to a second gain when the armature current is continuous, and according to a third gain when the armature current is in transition from the discontinuous to continuous conduction. The gains have proportional and integral terms and the integral term in the discontinuous and transition regions varies inversely to a current reference in the controller.

Abstract: A method for operating a DC motor controller according to a first gain when the armature current of the DC motor is discontinuous, according to a second gain when the armature current is continuous, and according to a third gain when the armature current is in transition from the discontinuous to continuous conduction. The gains have proportional and integral terms and the integral term in the discontinuous and transition regions varies inversely to a current reference in the controller.

Abstract: A microwave oven door is disclosed having a channel cross-section and formed of plastic material having a microwave impermeable viewing window, hinge means, door securing means, and a microwave impermeable coating in the channel cross-section area. An alternative embodiment has the channel cross-section area formed of a plastic filled with a microwave blocking material. A further embodiment has a microwave impermeable opaque surface in place of the viewing window.

Abstract: An improved system for mounting a magnetron exterior to a microwave oven chamber. A magnetron antenna extends through an orifice in the chamber wall and mounting clips extend from the chamber walls at locations spaced around the orifice. Apertures are provided within the keeper plate of the magnetron to allow the clips to pass therethrough and engage a keeper plate interface on relative rotation of the chamber wall and plate. The clips may be formed as part of the chamber wall.

Abstract: An electronic ballast system for operating fluorescent lamps at full and partial brightness is disclosed having a series reactance selectively switched into or out of the system by a reactance switch. The electronic ballast has an input filtering section, a voltage-clamped current source, and an oscillator whose frequency is determined in part by load reactance. Series filament capacitors provide lamp filament power control during starting and running at full and partial brightness.

Abstract: An eddy current coupling has a field coil (42) for magnetically coupling an inductor drum (26) and rotor (28). The thickness of the supporting arm (48) for the coil increases in a step-wise manner in a direction away from the end of the arm. The diameter of the adjacent portions (30) of the rotor is reduced in a corresponding manner to provide a plurality of air gaps (54a, 54b, 54c) across which the flux passes in radial directions. The flux passage and heat removal characteristics of the coupling are enhanced.

Abstract: A fused electrical plug for interconnecting appliances with a power supply (such as a conventional wall outlet). The plug includes at least neutral and positive terminal posts and may includes a ground terminal. The plug also includes a first body portion from which the neutral terminal post extends, the first body portion including a cavity for receiving a fuse. A second plug body portion carries the positive terminal post while a hinge secures the first and second plug portions for pivotal relative movement between an open position wherein the fuse receiving cavity is accessible in a closed position wherein the fuse receiving cavity is inaccessible. Electrical communication to the appliance is established via a fuse within the cavity and the positive terminal only when the first and second body portions are in the closed position. In a preferred embodiment, the first and second plug body portions are molded with the hinge being formed as a living hinge.

Abstract: An interlock switch assembly is disclosed having a unitary baseplate having relatively few moving parts and making use of conventional low cost miniature switches, each positively located and retained with respect to the baseplate. First and second actuators convert, respectively, linear motion of first and second operators into rotary motion to actuate the miniature switches. Switch actuation is prevented unless the properly timed motion of both operators is received by the actuators.

Abstract: A mounting system for suspending an appliance from an overhanging structure and, particularly, for suspending an appliance of the type having a housing including an upper surface and projecting rims extending away from the housing of opposite edges of the upper surface. The system includes a first bracket for attachment to the overhanging structure, the first bracket including a first lip for supporting one of the upper surface rims. A second bracket is in telescoping relation to the first bracket and includes a second lip for supporting the other of the upper surface rims. The first and second brackets are resiliently urged toward each other while the relative movement between the brackets is regulated. In a preferred embodiment, the relative movement between the first and second bracket is restricted by stops and prevented by a locking mechanism.

Abstract: A submersible motor is disclosed which is adapted for submersion within an environmental liquid and which has a gas-filled housing having first and second conduits each with proximate and distal ends and communicating with the interior of the housing for permitting ingress of gas into the housing through the first conduit and for discharging gas and accumulated liquid egressing from the housing above the surface of the environmental liquid through the second conduit to provide a visual indication of leakage rate when the first conduit is connected to a source of compressed gas at a pressure in excess of the ambient pressure at the level of submersion of the motor.

Abstract: A cable termination is disclosed for high voltage electrical cables for x-ray tubes having inner and outer conductive housings separated by resilient insulating material. The inner conductive housing is at or near the high voltage potential and is adapted to provide even voltage distribution in the insulating material. Electrical contacts are contained within the inner housing which make connection from the cable conductors to feedthrough conductors to complete the electrical path across the vacuum envelope of the x-ray tube.

Abstract: A microwave oven construction is disclosed wherein the oven cavity is assembled without the use of structural welds. A pair of pan shaped members, one forming the oven cavity top and the other forming the oven cavity bottom are placed edge to edge and crimped together to form a unitary cavity structure. An oven front panel is crimped to the cavity structure thus formed.

Abstract: A mounting system for securing a rotating anode of an x-ray tube against axial movement locates a bearing on a stud projecting from a tube end wall and secures the bearing on the stud by means of a threaded fastener which is accessed through a central bore of the rotating anode assembly prior to closure of the tube vacuum envelope.

Abstract: A browning heater for a microwave oven. The heater is comprised of a porcelain coated steel cover sheet, a foil resistance heater, a thermal insulation sheet and a stainless steel backplate bound together in order. The heater is mounted on the interior cavity roof of a microwave oven. The heater browns food by means of infrared radiation.