Blow molding apparatus

A blow molding apparatus that includes a preform supplying station for supplying preforms in an upright state, a heating station for heating the preforms to a suitable temperature condition for blow-molding while transporting the preforms, a blow station for blowing the heated preforms to form blow-molded products, and a collection station for collecting the blow-molded products, comprising:

• a first circular transportation passage that transports the preforms supplied from the preform supplying station at a first feed pitch;
• a first transfer mechanism that receives the preforms from the first circular transportation passage and changes the feed pitch to a second feed pitch that is wider than the first feed pitch while transporting the preforms along a second circular transportation passage;
• an inverting transfer mechanism that receives the preforms transported at the second feed pitch from the second circular transportation passage, inverts the preforms to an inverted state while transporting the preforms alone a third circular transportation passage, and then inserts mandrels into opening parts of the preforms in the inverted state from below;
• a second transfer mechanism that receives, from the third circular transportation passage, the preforms transported in a state where the mandrels are inserted and changes the feed pitch from the second feed pitch to the first feed pitch while transporting the preforms along a fourth circular transportation passage;
• an arc-shaped transportation passage part that is formed in the heating station and receives the preforms in the state where the mandrels are inserted from the fourth circular transportation passage;
• and
• a third transfer mechanism that receives the heated preforms from the arc-shaped transportation passage part and changes the feed pitch from the first feed pitch to the second feed pitch while transporting the preforms along a fifth circular transportation passage,
• wherein in the blow station, the preforms transported at the second feed pitch along the fifth circular transportation passage are received by blow-molding molds that are transported at the second feed pitch along a sixth circular transportation passage,
• the inverting transfer mechanism receives the blow-molded products from the blow-molding molds, withdraws the mandrels inserted in the opening parts of the blow-molded products in an inverted state downward while transporting the blow-molded products along the third circular transportation passage, and then inverts the blow-molded products in an inverted state to an upright state,
• the blow-molded products are collected from the inverting transfer mechanism by the collection station, and
• wherein the first, second, and third transfer mechanisms comprise:
• a turntable;
• a circular guide rail fixed to a surface of the turntable so that a center thereof is at a rotational center of the turntable;
• a plurality of sliders capable of sliding along the circular guide rail;
• holding parts formed on the respective sliders and hold the performs or blow-molded products;
• pivot pins that are rotatably disposed at intervals of a fixed angle on a circle that is concentric with the rotational center of the turntable in an inside position of the circular guide rail on the turntable;
• a plurality of swinging arms that swing along a surface of the turntable about the respective pivot pins as the turntable rotates;
• and
• slide-type linking parts that link swinging ends of the swinging arms to the respective sliders so as to allow the sliders to slide in an axial direction of the swinging arms.