Blow molding method and apparatus

A blow molding apparatus of a type in which an extruded parison is held by a split mold and the parison is formed after a configuration of a cavity of the split mold by blowing compressed gas in the parison, said apparatus comprising:

• a blow nozzle communicating with the inside space of the parison held by the split mold;
• and
• a blowing and cooling pipe provided in the central portion of the blow nozzle slidably relative to the blow nozzle for blowing compressed gas into the parison and being inserted into a swollen intermediate product for cooling it with the compressed gas further comprising a first reciprocating unit which causes the blow nozzle to communicate with the inside space of the split mold and a second reciprocating unit which inserts the blowing and cooling pipe into the swollen intermediate product, a reciprocating plane of the first reciprocating unit being offset from a reciprocating plane of the second reciprocating unit, said blow molding apparatus further comprising a moving table which is reciprocated by the first reciprocating unit, said moving table being constructed in the form of a box made by welding plates.