US Patent 7644777 Fire-fighting monitor

A fire-fighting monitor includes a housing, a nozzle coupler, and a pivot joint coupler comprising an internal passageway and a pivot member. The pivot member is pivotally mounted to the housing at the outlet of the housing. The nozzle coupler is mounted to the pivot joint coupler wherein the internal passageway of the pivot joint coupler is in communication with the internal passageways of the housing and the nozzle coupler, wherein the weight at the nozzle coupler generates a gravitational moment about the pivot axis. In addition, the nozzle coupler has a central axis defining a reference line, which is offset from the first pivot axis wherein a reaction force generated by fluid flowing through the nozzle coupler generates a moment about the first pivot axis in a direction opposed from said gravitational moment.