Blow molding trimming

A trimmer for nonround trimming of a blow molded container of the type made from an injection molded preform having an open end adjacent which the preform is held during blow molding thereof to include a nonround portion to be trimmed at a trimming plane, the trimmer comprising:

• a positioner for holding the container to position the nonround portion thereof for trimming;
• a rotary actuator that rotates about a rotary axis for rotating perpendicular to the trimming plane of the container as it is held by the positioner;
• a knife holder arm assembly pivotally supported by the rotary actuator about an arm axis spaced from the rotary axis, the arm assembly including a knife holder that holds a knife for trimming the container, and the knife holder including a pair of rollers;
• a spring for biasing the arm assembly so the knife holder is biased toward the rotary axis during rotation of the rotary actuator;
• and
• a guide on the positioner for engaging the rollers of the knife holder under the impetus of the spring during rotation of the rotary actuator so the knife held thereby moves in a nonround path to cut through the nonround portion of the container and thereby trim a scrap piece from the container.

A trimmer for nonround trimming of a blow molded container of the type made from an injection molded preform having an open end adjacent which the preform is held during blow molding thereof to include a nonround portion to be trimmed at a trimming plane, the trimmer comprising:

• a positioner for holding the container to position the nonround portion thereof for trimming;
• a rotary actuator that rotates about a rotary axis for rotating perpendicular to the trimming plane of the container as it is held by the positioner;
• a knife holder arm assembly including a first arm pivotally supported on the rotary actuator, a first spring that biases the first arm about the rotary actuator, and wherein the knife holder arm assembly further includes a second arm pivotally supported on the first arm, a second spring that biases the second arm about the first arm, and a knife holder pivotally supported by the second arm to hold a knife for trimming the container, and the knife holder including a pair of rollers;
• a guide on the positioner for engaging the rollers of the knife holder under the impetus of the springs during rotation of the rotary actuator so the knife held thereby moves in a nonround path to cut through the nonround portion of the container and thereby trim a scrap piece from the container;
• and
• a scrap holder connected to the rotary actuator for holding the scrap piece upon trimming thereof from the container.

A method for trimming a nonround blow molded container of the type made from an injection molded preform having an open end adjacent which the preform is held during blow molding thereof to include a nonround portion to be trimmed at a trimming plane, the trimming method comprising:

• positioning the container using a positioner so the nonround portion thereof is accessible for the trimming;
• rotating a rotary actuator about a rotary axis that extends perpendicular to the trimming plane of the container as it is held by the positioner;
• pivotally supporting a knife holder arm assembly and a knife held thereby on the rotary actuator about an arm axis spaced from the rotary axis;
• biasing the knife holder arm assembly using a biase so the knife held thereby is biased toward the rotary axis during rotation of the rotary actuator;
• and
• guiding the knife holder arm assembly under the impetus of the biaser during rotation of the rotary actuator so the knife held by the arm assembly moves in a nonround path to cut through the nonround portion of the container and thereby trim a scrap piece from the container.

A method for trimming a nonround blow molded container of the type made from an injection molded preform having an open end adjacent which the preform is held during blow molding thereof to include a nonround portion to be trimmed at a trimming plane, the trimmer comprising:

• positioning the container using a positioner so the nonround portion thereof is accessible for the trimming;
• rotating a rotary actuator about a rotary axis that extends perpendicular to the trimming plane of the container as it is held by the positioner;
• pivotally supporting a knife holder arm assembly and a knife held thereby on the rotary actuator about an arm axis spaced from the rotary axis;
• spring biasing the knife holder arm assembly so the knife held thereby is biased toward the rotary axis during rotation of the rotary actuator;
• guiding the spring biased knife holder arm assembly by rollers thereon biased against a guide on the positioner during rotation of the rotary actuator so the knife held by the arm moves in a nonround path to cut through the nonround portion of the container within a cutting groove thereof and thereby trim a scrap piece from the container;
• and
• holding the scrap piece upon trimming thereof from the container.