Abstract: A pressure sensor for sensing changes in pressure in an enclosed vessel may include a first chamber having at least one expandable section therein that allows that first chamber to change in length. A reference member mounted within the first chamber moves as a result of changes in length of the first chamber. A second chamber having an expandable section therein allows the second chamber to change in length in response to changes in pressure in the enclosed vessel. The second chamber is operatively associated with the first chamber so that changes in length of the second chamber result in changes in length of the first chamber. A sensor operatively associated with the reference member detects changes in position of the reference member. Changes in position of the reference member are related to changes in pressure in the enclosed vessel.

Abstract: An audio frequency distribution and adjusting circuit includes a variable resistor network having a first variable resistance and a second variable resistance coupled in series between a first resistor network terminal and a second resistor network terminal. The variable resistor network also includes a wiper contact with the first variable resistance and the second variable resistance for adjusting the total resistance between the resistive network terminals. The variable resistor network terminals are coupled in parallel with a low-pass filter, which is coupled to a low-frequency driver. The resistor network wiper contact is electrically coupled to the input of the high-pass filter, which is coupled to a high-frequency driver.

Abstract: The present invention provides an earth anchor to secure a cover over a trench or hole in the ground. The device has a retaining cap which is attached to a rod. Extendible arms are connected to the rod below the cap. The end of the rod opposite the cap is inserted into the hole or trench until the cap rests at ground level, either on separate cover plates or on the ground itself. For large holes, the cap retains separate cover plates over the hole; for small holes, the cap acts as a cover itself. The arms are extended by a jack screw, rack and pinion, or other means until they contact the substrate or underside of the cover plates and clamp the same between the cap and the arms. The cover can be removed by reversing the motion of the jack screw or rack and pinion, and retracting the arms, thereby freeing the device to be removed from the whole.

Abstract: A stripper for removing photoresist or solder masks has a composition of 30-80% by weight of a propylene glycol ether; 10-60% by weight of a pyrrolidone; 0.1-5% by weight of potassium hydroxide; 0.1-10% by weight of a surfactant; 0-20% by weight 1,3-butanediol; 0-10% by weight 2-(2-aminoethoxy) ethanol; and a water content of <1%.

Abstract: The signal from a piezo-electric transducer in an electro-acoustic guitar is modified by a variable depth notch filter. The notch filter includes two paths between an input and a summation circuit. The signals in the two paths are 180.degree. out of phase and one of the paths includes a bandpass filter. The notch is located at approximately 5 khz. The depth of the notch depends upon either the broadband amplitude or the narrowband amplitude of the signal from the transducer and the depth of the notch is controlled using either feedback or feedforward control.

Abstract: A powered wheelchair ramp includes a drive mechanism having a gear, a cam, and a lever arm keyed to a common shaft to prevent relative motion among these elements. An electric motor drives the gear through a clutch and the lever arm raises or lowers a folding ramp. Energy storage device engage the cam through a follower for storing energy as the ramp is lowered. The energy storage device also damps the motion of the ramp. When the ramp is raised, the energy storage device aids lifting the ramp. The torques applied to the common shaft are such that the net torque in either direction about the shaft is below a predetermined amount. The result is that the ramp can be raised and lowered easily, even by a single person in a wheelchair sitting beside the ramp. The clutch is released for manual operation and can engage at any point for powered operation.

Abstract: In a process for making an EL lamp, a rear electrode is roll coated on a temporary substrate, followed by successive roll coatings of a dielectric layer and a phosphor layer. A transparent, conductive layer on a transparent substrate is laminated to the phosphor layer layer and the temporary substrate is removed. The layers are applied from a slurry or ink and bladed to a uniform thickness across the width of the temporary substrate. The process can be continuous using rolls of material for the temporary substrate. The length of a lamp is limited by the length of the temporary substrate. The width of the lamp is determined by the size of the apparatus used to apply and to spread the layers.

Abstract: A process management system is described for creating and executing graphically depicted communication processes. The process management system includes a graphical process editor facilitating the creation of communication processes on a graphical user interface. The graphically depicted communication processes visually represent to a process programmer the relationships between the events comprising the communication process. A process manager executes a set of events comprising both scheduled events and control events corresponding to the graphically displayed events. Furthermore, the process manager may operate in an immediate or real time mode to process the events of the communication process.