Abstract: A portable cooler 10 includes an insulated body 12 presenting an interior space and an open top, and an insulated cover 14 for closing off the body. A storage compartment 16 extends through an opening 26 in the side wall 20 of the body into the interior space, and includes top, bottom and side walls 28, 30, 32 that are spaced from the bottom and side walls 18, 20 of the body and exposed to the interior space to define a dry cell within the storage compartment. An insulated compartment cover 36 closes off the opening in the side wall of the body and is movable relative to the body to provide access to the dry cell so that articles to be stored in the cooler can be isolated from the ice and water that is retained in the interior space of the cooler body.

Abstract: A pressure relief vent on a container includes a flat diaphragm fastened to the exterior of a container so as to cover an opening in the container. The diaphragm is fastened to the container at its perimeter and at at least one point within its perimeter. The shape of the peripheral fastening seam and the number of and size of the point fastenings determine and stabilize the vent pressure at which the diaphragm ruptures.

Abstract: In the manufacture of prestressed concrete pipe, wire is wound under tension around the concrete body of the pipe and secured thereto. In accomplishing this the concrete pipe is mounted on a turntable for rotaton about the longitudinal axis of the pipe and wire under tension is wrapped thereon in a helical fashion from one end to the other.