Abstract: A simple, compact counterweight mechanism for a lid for a sub-surface container. A straight rigid beam extends from front to rear within the container. Front portions of the beam are connected to the overlying lid, middle portions of the beam are pivotally connected to the container and rear portions of the beam are pivotally connected to a pair of rearwardly extending control arms, which are pivotally connected at their rear to a depending counterweight.

Abstract: The present invention pertains to a liquid fifth wheel assembly for use with tractor and trailer combinations wherein the trailer includes a tank body for the storage and transportation of fluids, and the tractor includes a pumping station adapted to deliver the fluid stored in the tank. The fifth wheel assembly which is secured to the under side of the trailer has a central opening therein through which passes an enclosed dual concentric suction and discharge pipe structure interconnecting the tank and the pump station; the pipe structure including a swivel joint for permitting angular displacement of a portion of the enclosed pipe.