Abstract: A metal detector employing static discrimination. Within the scope of the invention is a two-frequency method and apparatus for discriminating between metal objects and ground. Also within the scope of the invention is a three-frequency method and apparatus for discriminating between ferrous and non-ferrous metal objects. The methods and apparatus do not require movement of the search head of the metal detector.

Abstract: A helmet headset system for use with an audio system and a helmet. The helmet headset system comprises a mount for mounting to the helmet, and first and second audio signal conduits, e.g. each comprising a coil cord, and each having first and second ends. The first end of the first audio signal conduit is coupled to the mount. The first end of the second audio signal conduit is detachably coupled to the second end of the first audio signal conduit, and the second end of the second audio signal conduit is detachably coupled to the audio system. In a related aspect, the system may comprise a single, detachable audio signal conduit. Related methods also are provided.

Abstract: A method and apparatus for distinguishing metal objects employing multiple frequency interrogation. In one aspect, the method includes interrogating a target with at least two frequencies, obtaining respective response signals for the two frequencies, resolving the response signals into at least respective resistive component portions, comparing the magnitudes of at least two of the resistive component portions, selecting one response signal from among the response signals based on the comparison, and characterizing the target with the selected response signal. In other aspects, the method includes obtaining response data by interrogating the target at at least two frequencies, normalizing the response data and comparing the normalized response data. A signal is provided indicating the extent of any disagreement in the normalized response data.

Abstract: The present invention is a circuit and method for reducing switching and reverse recovery losses in the output rectifiers while creating zero voltage switching conditions for the primary switchers. There are described two output configurations, one employing a soft commutation inductor element a bridge rectifier and a output filter capacitor, the second using a soft commutation inductor element a rectification-filtering bridge composed by two capacitors and two capacitors. Both secondary circuits can be driven by three primary circuits. A first circuit is a full bridge with phase shift control, and a second circuit is a half bridge topology with an additional bydirectional switch which achieves two goals, on to get soft switching commutation across all the primary switches, the second to create the right waveforms in the secondary suitable with the claims in this invention. The third topology is a phase shifted two transistors forward.

Abstract: A method and apparatus for reducing contamination in a plastic container. A coating is provided for the container serving two functions. First, it causes the surface of the container to wet more easily. Second, it reacts with organic molecules emitted from the container so as to render them harmless to the contents stored inside the container.

Abstract: A multiple-axis imaging system having individually-adjustable optical elements and a method for individually adjusting optical elements of the system. The system comprises a plurality of optical elements having respective optical axes and being individually disposed with respect to one another to image respective sections of an object, and a plurality of individually-operable positioning devices corresponding to respective optical elements for positioning the optical elements with respect to their respective optical axes. The positioning devices are specifically adapted to adjust the axial position, lateral position and angular orientation of the optical elements with respect to their respective optical axes. The system is particularly adapted for use as a microscope array, and the positioning devices may be micro-actuators.

Abstract: A lightning detection and data acquisition system. A plurality of remote programmable sensor is utilized to detect cloud to ground and IC lightning strikes. Analog representations of the lightning strikes are converted to digital signals. The digital signals are classified according to user changeable criteria. The classified digital signals are compressed and optionally decimated. The compressed information is transmitted to a central location where it is decompressed and used to correlate the location, magnitude, and travel path of the detected lightning strikes.

Abstract: A lightning detection and data acquisition system. A plurality of remote programmable sensor is utilized to detect cloud to ground and IC lightning strikes. Analog representations of the lightning strikes are converted to digital signals. The digital signals are classified according to user changeable criteria. The classified digital signals are compressed and optionally decimated. The compressed information is transmitted to a central location where it is decompressed and used to correlate the location, magnitude, and travel path of the detected lightning strikes.

Abstract: A dynamic diffractive optical transform. An electric field pattern is created across a body of material, the material being characterized in that it has an optical transmission property which varies in response to of an electric potential applied across a portion thereof. The electric field pattern is created such that the resulting profile of the transmission property is an arbitrary shape which produces a desired diffraction pattern that may not be physically realizable in conventional refractive optics or is a Fresnel lens-like construct derived from a refractive optical element. This is done by selectively applying electric potentials to transparent electrode pairs having liquid crystal material therebetween and preferably relatively small proportions in relation to the relevant wavelength of light, so as to create variations in phase delay that are aperiodic, have other than fifty percent spatial duty factor or have multiple levels of phase delay.

Abstract: A ring slicer having an easily removable knife and knife assembly. Within the scope of the invention, there is an apparatus for cutting an article of wood, comprising a ring assembly comprising two end plates and a plurality of knife assemblies. Each knife assembly comprises a knife, a base, and a clamp for clamping the knife to the base. The assemblies are provided for installation between the end plates. According to one aspect of the invention, the bases include one or more first apertures and at least one of the end plates includes a corresponding set of one or more second apertures therethrough for receiving respective dowel pins. The first apertures are adapted to snugly slidingly receive the respective dowel pins. According to another aspect of the invention, for each knife assembly, the clamp includes an upper clamping member that is mounted to the base so that a portion of the upper clamping member is cantilevered from the base.

Abstract: A paint shaker and motor therefor. A yoke has at a first end a clamp for clamping a paint can and at a second end, is pivotally connected to a linkage assembly that converts the linear motion of a reciprocating linear motor to an arcing motion of the yoke. The motor includes a cylinder and a piston that is spring biased toward an inlet end of the cylinder. Compressed air enters the inlet end and a passageway through the piston for conducting the compressed air to a valve having a displaceable stopper, wherein the compressed air seats the stopper in the valve and thereby closes the valve, so that air pressure moves the piston toward an outlet end of the cylinder. The outlet end of the cylinder includes a projection against which the piston drives the stopper so as to unseat the stopper in the valve and thereby open the valve, permitting the spring bias to return the piston toward the inlet end of the cylinder.

Abstract: A method for locating and inspecting underground or other nonvisible, non-electrically conductive pipes. An electrolyte is introduced into the pipe and a time varying electrical signal is applied to the fluid as in a standard prior art method for locating underground pipes, wherein proximity to the pipe is determined by assessing the strength of the electromagnetic field produced thereby. The method also provides for detecting leaks by introducing the electrolyte relatively slowly, to ensure that a pool of the electrolyte accumulates outside the pipe adjacent the leak.

Abstract: An expansion bolt. In a preferred embodiment, the expansion bolt includes a center chock having either a convex or a concave outer ramping surface and two outer chocks disposed about the center chock having complementarily concave or convex outer ramping surfaces.

Abstract: A method and apparatus for planing an article of wood. Specifically disclosed is a cutting head adapted for rotation about an axis, and at least one elongate knife including a linear cutting edge for cutting the wood. The cutting edge terminates at opposite ends of the knife in respective tips. The knife is held by the cutting head so that each tip is rotated about the axis of rotation at the same fixed radius. However, the cutting edge is misaligned by a predetermined bias angle with respect to the axis of rotation. Where a plurality of the cutting heads are stacked or ganged together, preferably, the angle of misalignment for the knives of some of the cutting heads is reversed from the angle of misalignment for the knives of others of the cutting heads.

Abstract: An adjustable profiling head for a wood cutting apparatus. There is a first body portion for carrying a plurality of first knives and a second body portion for carrying a plurality of second knives. The cutting edges of the knives define respective cutting surfaces of revolution about an axis that have different mean diameters for the two body portions. In one aspect of the invention, the body portions are adapted to receive the respective knives by associated knife clamping mechanisms that are adapted to be removably mounted to the body portions with one or more first control plates therebetween, for adjusting the radial positioning of the knives. In another aspect of the invention, the body portions are adapted to be removably mounted to each other so that the body portions are disposed axially adjacent one another with one or more second control plates therebetween, for adjusting the relative axial positioning of the knives of one of the body portions with respect to the knives of the other body portion.

Abstract: A chip and method for producing wood pulp. First, second and third pairs of substantially parallel sides are formed by cleaving, cutting and cutting, respectively. The sides of the second pair of sides are cut by a first knife so as to be spaced between about 2 to 8 mm. The sides of the third pair of sides are cut by a second knife so as to be spaced a greater distance apart than the first pair. The sides of the first pair of sides are cleaved substantially along the grain direction so as to be spaced also a greater distance apart than the sides of the first pair. The sides of the third pair of sides are cut so as to be substantially perpendicular to the sides of the first pair of sides.

Abstract: A hybrid thermionic valve and solid state audio amplifier. A complete tube amplifier is scaled to produce a relatively low power yet also retain its small and large signal distortion characteristics. The output of the scaled amplifier is amplified by a relatively linear solid state amplifier. In one embodiment of the invention, a plurality of tube amplifiers are coupled in parallel and input to a mixing circuit for selectably mixing the outputs of the tube amplifiers and providing the mixed outputs to the solid state amplifier.

Abstract: A method and apparatus for profiling a log. In a profiler having first and second knives disposed on a rotating disc, a mounting member is adapted to mountably receive both the first and second knives so that each blade has a point on its cutting edge that is proximate a point that is on the cutting edge of the other knives. Preferably, the points are end most points and abut one another.

Abstract: A multiple circuit board package employing solder balls and method and apparatus for fabricating same is described. Two or more printed circuit boards and a plurality of electronic devices are joined together using solder balls. Alternatively, three or more printed circuit boards are joined together using the solder balls. A novel and improved solder ball connection is disclosed, along with a fixture for aligning and fixing the disposition of the pads and the solder balls during a heating cycle in which the circuit boards are placed under pressure while the solder balls are re-flowed for making an electrical connection.