Abstract: A pizza warmer and oven system in which a plurality of pizza warmers containing a phase change material can be charged to their preferred temperatures by resistance heaters positioned in shelves above and below each warmer in an oven. One embodiment has top shelves biased in close proximity with the warmers. Moving a lever causes the upper shelves to be raised by cams, allowing removal or insertion of warmers. Insertion of warmers into the oven trips switches, starting timing circuits which energize the heater and charging indicator lights. At the end of the timing cycle, indicator lights signal the warmer's charged condition. In another embodiment, the top shelves are gravitationally biased down but are each free to move upward slightly for warmer insertion or removal. Turning on the oven energizes the heaters. A thermostat in the heater circuit turns off the heater at a pre-selected temperature.

Abstract: A heating device for food and other products is provided. The device includes a unit containing a rechargeable phase change material which is capable of being charged with heat energy by a heat source such as a conduction, convection, radiant heat, electrical resistance, electrical inductance, microwave, or radio frequency. The phase change material may be provided in a variety of forms and may comprise linear alkyl crystalline alkyl hydrocarbons, alkyl hydrocarbon waxes, crystalline fatty acids, linear crystalline primary alcohols, ethylene copolymers, polyethylene, polyethylene glycol, polyethylene oxide, and acetamide.

Abstract: A rechargeable phase change material unit is provided. The unit comprises a first shell portion and a second shell portion forming a hollow shell defining a cavity. At least one layer of a phase change material is disposed in the cavity of the shell. The phase change material is capable of being charged with heat energy. A heater assembly is positioned on one side of the layer of phase change material. The heater assembly is provided to charge the phase change material with heat energy and distribute heat energy throughout the layer of phase change material during the charging of the phase change material.

Abstract: Sensors distributed along a ropeway communicate with a base station and preferably a base station computer. One type of sensor detects and signals cable misalignments from a normal line of cable traction. Preferably each cable tower has at least one such sensor. Another type of sensor is mounted on a sheave assembly and detects vibrations characteristic of disintegration within the assembly. It produces a sheave problem signal whenever such occurs. Preferably there is one vibration sensor mounted on each sheave assembly. Another type of sensor is preferably mounted on each ropeway carrier for detecting and signaling excessive swings. The sensor signals are communicated to a cable operator so that remedial action can be taken. Each carrier sensor has an RF transmitter for broadcasting its signals to RF receivers mounted on cable towers. Interface units local to sensor groups relay their signals to a base station computer that provides corresponding indicators to the cable operator.

Abstract: A method and apparatus for laminating multilayer printed circuit boards having both rigid and flexible portions. The multilayers of a multilayer printed circuit board are positioned on a lower lamination plate which rests on a bleeder plate which itself rests on a vacuum plate. The circuit layers are then covered with another steel plate, a sheet of silicon material, a breather blanket and a plastic vacuum bag which is hermetically sealed to the vacuum plate using a silicon sealing material. The vacuum plate and the components thereon are positioned within a pressure vessel, a vacuum line is connected to the vacuum plate and the multiple layers of the multilayer printed circuit board are laminated within the pressure vessel.

Abstract: An apparatus for laminating multilayered printed circuit boards while radically reducing the volume of inert gas that must otherwise be used to effect the lamination process. The invention employs a novel ring assembly, each such assembly disposed on a moveable, horizontally disposed shelf. Each such ring assembly comprises a hollow circular cylinder, the interior of which is adapted to radially enclose a multiple layer circuit module mounted on a heating platen. The axial surfaces of the cylinder are capped by a pair of seal plates and O-rings to form a gas-tight laminating chamber. Each shelf is adapted to travel vertically along a pair of support tubes whereby the entire array of shelves may be compressed relative to the respective shelves by a hydraulic or pneumatic cylinder the rod of which is affixed to the bottom surface of the lowermost shelf.

Abstract: Materials exhibiting electrostrictive characteristics, such as piezoelectric materials, are used to selectively increase the mechanical engagement forces between two electrical connections for improving the integrity and reliability of their interconnection. In one illustrative embodiment, a piezoelectric layer is located beneath each connection pad of a printed circuit board and separated therefrom by a layer of dielectric material. The respective piezoelectric layers are commonly connected to a source of voltage for selectively increasing their geometric dimension thereby also increasing the force of engagement between the connection pads and a suitable connector.

Abstract: The inconsistent etch-back characteristics of conventional plasma treatment of multilayered printed circuit boards, are overcome by use of a shield, preferably of aluminum, temporarily affixed to each surface of the circuit board during the plasma desmear and etch process. The shield is sufficient size to overlap virtually the entire circuit board and contains an aperture pattern which is substantially congruent with the aperture pattern of the circuit board. The shield affects the plasma process, rendering the etch-back effect substantially homogeneous and consistent throughout the circuit board irrespective of the location of each etched aperture on the circuit board. Alternative embodiments include a wire mesh which obviates the congruent hole pattern requirement and use of a low D.C. bias voltage to further regulate and control the plasma effect.

Abstract: An apparatus for automatically testing printed circuit boards on which the test points are locatable at row and column intersections of a grid is described. The apparatus has two bars mounted above the printed circuit board in parallel alignment with the columns of the possible test points. Each bar has a set of probe contacts depending therefrom which can be placed into contact with the test points on the printed circuit board located along a single column. The bars are movable relative to the printed circuit board and may be sequentially placed into contact with any selected pair of columns of possible test points. Test voltages are sequentially applied to selected pairs of the probe contacts, enabling the electrical characteristics between the pairs of test points on the printed circuit board to be measured. A micro-processor is used to control the testing sequence and in correlating the results.

Abstract: An electronic watch case is disclosed which comprises an inner-cover disposed within the case and switch means extending through the case. The inner-cover comprises a circular metallic member having resilient tab portions, resilient finger portions, and an aperture therein. The inner-cover is positioned with respect to the switch means and the watch batteries so that when the switch means is engaged from the exterior of the case, the batteries in the watch module are electrically coupled to associated electrical contacts. When the switch means is disengaged, it is returned to an unactuated position by the urging of one of the resilient finger portions, thereby electrically decoupling the contacts from the batteries.