Unit dose assembly

A cap and tube assembly device, comprising:

• a tube for containing a product;
• a nozzle having a one end mounted to one end of said tube and having a thin wall section puncturable to provide a discharge on the other end;
• said nozzle having a non-threaded outer nozzle surface with a smaller axial cross section than said tube, the junction of said tube and said nozzle defining an inclined surface of transition to permit flow without cavitation from said tube to said nozzle;
• a cap having an inside non-threaded cap surface with a cross section sized to slidably engage said nozzle and having an outside cross section less than the inside cross section of said tube;
• said cap having an axially centered puncture means positioned in a first position spaced from said thin wall and movable to a second position to puncture said thin wall said nozzle surface and cap surface mating to locate said first position;
• wherein the outside of said nozzle is provided with a surface of resistance and the inside of said cap has an interference surface, whereby said surface of resistance and said interference surface cooperate to selectively maintain said puncture means in said first position;
• said puncture means having a chisel shaped edge for forming an axially centered hole in said wall without removing or fragmenting said wall;
• and
• means positioned in said tube including a plurality of stacking ribs attached to said inclined surface of transition for preventing entry of said cap into said nozzle when a plurality of said assemblies are stacked one on another.