A multichannel pipe of reduced wall thickness and increased rigidity consists in a plurality of elongated strips welded along their lateral edges to one another. The strips are of arcuate shape in a direction transverse to their length to form a tubular structure. Webs extend from each juncture of two strips across the pipe to another juncture. The angles included by the arcs of the strips are such that the angle at which the strips and the webs meet is larger than 90.degree. . The radius of curvature of the arcs on which the strips are curved is less than the radius of a circle having the same cross-sectional area as the pipe. In the preferred method of manufacture of the pipe the web structure is assembled and the arcuate strips then welded to one another and the ends of the webs.
A tube length which is divided into two separate passages by a longitudinally extending wall. The tube is formed by the steps of providing diametrically opposed longitudinal slots in the walls of a tube with the slots extending somewhat less than the entire length of the tube to leave solid portions thereof at either end, positioning a metal plate within the slots, welding the plate to the tube walls, subsequently machining the outer cylindrical surface of the tube to provide a smooth surfaced tube of the desired external diameter, removing both end portions of the tube to leave a tube portion having the dividing wall along its entire length, capping both ends of the tube, and providing a plurality of holes in the tube walls on either side of the plate.
A waveguide having reduced windloading yet a relatively wide bandwidth for the dominant mode of propagation comprises an elongated cylinder having substantially parallel plates forming an interior waveguide portion which in cross-section is a doubly-truncated circle. The plates are symmetrically disposed about the central axis of the elongated cylinder.
A gas-insulated transmission line including an elongated outer sheath and a plurality of elongated inner conductors disposed within the outer sheath. An insulating gas electrically insulates the conductors from the sheath, and support means insulatably support the conductors within the sheath. The interior of the outer sheath is separated into a plurality of discrete compartments by walls, with each compartment having disposed therein one of the inner conductors. The compartmentalization of the outer sheath minimizes the possibility of a fault being transferred from one inner conductor to the other conductors.
An improved culvert drainpipe and method of utilizing the same is disclosed characterized by use of an elongate thin wall extruded drainpipe element formed having a generally S-shaped configuration defining a pair of main flow channels and including plural curvilinear projections extending axially along the exterior of the element. The distal edges of the drainpipe element cooperate with one or more elongate wall extensions formed on the interior of the drainpipe element which prevent radial compression and/or collapse of the drainpipe element and deter debris from entering into the main the flow channels. In use, multiple drainpipe elements are bundled together in a generally parallel axis orientation whereby the curvilinear projections serve as secondary flow channels, improve debris segregation, and maintain space between adjacent drainpipe elements.
A chiropractic device for concurrently massaging and exercising a user comprising elongated hollow cylindrical tubes fabricated of a rigid metallic material. Each tube has a length with an external diameter and an internal diameter with an aperture through each tube. A plurality of welds are provided. Each weld is of a linear extent corresponding to the length of the tubes. The welds couple to and secure together the three tubes along their contacting lengths to form a cluster of tubes in a triangular configuration with each tube coupled to the other two tubes along their entire contacting lengths.
