Abstract: A ventilation system for a diazo copy machine of the type having an exposure chamber containing a source of illumination for exposure of an original image onto diazo copy material and developer chamber utilizing ammonia vapors to develop the image on the diazo copying material. The ventilation apparatus comprises separate means for ventilating the exposure chamber and for ventilating the developing chamber. Inlet means are provided in the exposure chamber for admitting ambient air thereinto, and outlet means are provided for venting hot air from the exposure chamber into the ambient environment. Vacuum means are provided for exhausting ammonia-laden air from the developing chamber, and an absorber chamber is provided which is in fluid communication therewith, cartridge means being disposed within the absorber chamber for selectively absorbing ammonia fumes. Ammonia-laden fumes are drawn from the developing chamber into the absorber cartridge and then exhausted into the ambient environment.

Abstract: A collapsible wall closure for a dispenser nozzle comprised of a stiff but resilient tube section adapted to be bent over and latched in the bent position to provide a fluid tight closure of the nozzle by collapse of the tube wall. The interior of the nozzle tube is undercut in the region of the wall collapse on either side of the tube along the fold line of the tube, in order to provide complete sealing collapse of the tube wall in the bent position. The undercuts are comprised of shallow grooves extending axially along the tube interior thinning the tube wall thickness in the region of the wall collapse. A pair of closures are incorporated in a cap closure particularly adapted to an ammonia hydroxide container for connection to vapor-type diazo reproduction machines.