Apparatus for preventing leakage from open ended mixers or agitators

Bib for preventing leakage from open end mixers

Rotary cutter means having positive indexing drive

Drive system for rotary cutter arm

Mixer drum support structure for truck concrete mixer

Breather system for a sealed storage structure

Indicating and monitoring means for detecting condition of sealed storage structures

For detecting the functioning of a sealed storage structure, a sealed housing is secured to the exterior of an airtight storage structure immediately above an entrance doorframe. A tube is interconnected to the bottom wall of the housing and the top cross member of the doorframe to provide communication between the interior of the storage structure and the housing. An inflatable monitoring bag is secured within the housing and connected by a vent tube to the exterior of the housing. The interior of the monitoring bag is subjected to the atmospheric pressure and the exterior of the bag is subjected to the structure pressure. The physical condition of the monitoring bag during any given period provides an indication of whether the storage structure is experiencing a pressure cycle.