Abstract: The present invention is a waveguide device having a body of molded, foam plastic with a speaker end and an open end and an even number of segments with a flat surface in a plane parallel to the speaker end. The segments have inside wall surfaces which flare increasingly outwardly from the speaker, and these inside wall surfaces have a speaker end length, L.sub.1, determined by the following formulas, L.sub.1 minimum=0.7.times.w.sub.s /0.0012 g/cm.sup.3 .times.1/A.sub.SE, and L.sub.1 maximum=1.2.times.w.sub.s /0.0012 g/cm.sup.3 .times.1/A.sub.SE, wherein L.sub.1 is a straight line length of the lower portion of the segment wall surface, w.sub.s is the weight of a speaker cone in grams/cm.sup.3, and A.sub.SE is the cross-sectional area of the speaker end in square centimeters. The waveguide body also includes an end plate with a speaker face and anchor inserts for attachment of a speaker thereto. The anchoring inserts are embedded in the waveguide body.

Abstract: The present invention is directed to an improved high frequency acoustic speaker center cone, which may be located at a speaker coil tubular support, tube wherein the cone has a plurality of thin, pie-shaped segments radiating outwardly with each of the segments having an arcuated cross-section, so as to create a convex shape towards its center. The segments are highly concave toward the center and less concave with increasing radial distance away from the center. The width of the segments may increase linearly with radial distance so as to create a constant acoustical resistance radially. The center cone also has a thickness gradient with increasing thickness radially towards its center. In another embodiment, the present invention is directed to a system containing both the aforesaid center cone, an outer cone with similar radial characteristics but being concave towards its center. The segments of the outer cone preferably terminate at a flexible, high sound absorption ring.

Abstract: The present invention is a waveguide for an acoustic speaker having a predetermined cone weight. The waveguide body has a speaker end and an open end and an even number of segments with a flat surface in a plane parallel to the speaker end. The segments have inside wall surfaces which flare increasingly outwardly from the speaker, and these inside wall surfaces have a speaker end length, L.sub.1, determined by the following formulas, L.sub.1 minimum=0.7.times.w.sub.s /0.0012 g/cm.sup.3 .times.1/A.sub.SE, and L.sub.1 maximum=1.2.times.w.sub.s /0.0012 g/cm.sup.3 .times.1/A.sub.SE, wherein L.sub.1 is a straight line length of the lower portion of the segment wall surface, w.sub.s is the weight of a speaker cone in grams/cm.sup.3, and A.sub.SE is the cross-sectional area of the speaker end in square centimeters. Each of the segment inside wall surfaces has an outer end length L.sub.2 which has a predetermined length related to L.sub.1.

Abstract: A laminating machine for laminating layers of plastic film about an insert has cold feed rollers, a preheater and heated expeller rollers. The workpiece to be laminated is fed to the preheater by the feed rollers and is heated to a temperature just below the melting point of the adhesive on the plastic film. The heated workpiece is then fed to the hot expeller rollers which apply heat and pressure to finish melting the adhesive and squeeze any air bubbles out of the workpiece. Temperature controls assure that no melting and thus, no pre-lamination occurs at the preheater. The preheating step results in a laminating machine with high throughput of high quality laminations, even with inserts impervious to air.

Abstract: A pipeline pig inspection device having a plurality of pressure chambers for detecting pipeline leaks and eliminating erroneous indications of leaks caused by obstructions within the pipeline, significant changes in pipeline diameter, and minor fluid flows through the pig which are not caused by leaks.

Abstract: An ultrasonic inspection method and apparatus for inspecting test objects such as pipeline girth welds are disclosed. Ultrasonic transducers are carried by a track circumferentially mounted around the pipeline. The transducers are mounted in a hollow, open-ended housing and a flexible seal fixed to the housing retains coupling liquid between the transducers and the pipeline to permit the propogation of waves between the transducers and the weld. An adjustable pressure regulating device maintains substantially constant liquid pressure within the housing in order to minimize the loss of coupling liquid and yet insure adequate coupling between the transducers and the weld.