Method and apparatus for detecting defects or deterioration in the sidewalls of can bodies

A method of operating a can bodymaker to mitigate the occurrence of defects in the sidewalls of can bodies during production of the can bodies within the can bodymaker, each can body being formed by pushing a cup, mounted on a punch of a reciprocating ram, through one or more dies contained within a tool pack of the bodymaker, the method comprising:

• obtaining output signals from sensors outside of the toolpack and arranged around the ram axis adjacent to an exit end of the tool pack;
• processing the output signals to detect passage of open ends of can body sidewalls past the sensor(s) and thereby determine measures of the heights of can body sidewalls;
• analysing the determined measures to identify can body sidewall defects;
• and
• adjusting one or more operating parameters of the bodymaker, or of another component of a production line within which the bodymaker is located, to mitigate the occurrence of defects, wherein the sensors comprise a plurality of sensors spaced angularly apart from one another around the ram axis and the determined measures comprise measures of the height of the sidewall of a can body for more than one location around the circumference of the can body, thereby a detecting sugar scoop defect.

A system for producing can bodies from cups, the system comprising:

• a can bodymaker for forming a can body by pushing a cup, mounted on a punch of a reciprocating ram, through one or more dies contained within a tool pack of the bodymaker;
• a housing disposed adjacent to the tool pack and within which are mounted sensors, the housing and sensors being attached within the can bodymaker such that the or each sensor is arranged around the ram axis adjacent to an exit end of the tool pack;
• and
• a computer processing unit in wired or wireless communication with the or each sensor to receive therefrom the output signals of the sensor(s) and being configured to process the output signals to detect passage of open ends of can body sidewalls past the sensor(s) and to thereby determine measures of the heights of can body sidewalls, to analyse the determined measures to identify can body sidewall defects, and to adjust one or more operating parameters of the bodymaker, or of another component of a production line within which the bodymaker is located, to mitigate the occurrence of defects, wherein the sensors comprise a plurality of sensors spaced angularly apart from one another around the ram axis and the determined measures comprise measures of the height of the sidewall of a can body for more than one location around the circumference of the can body, thereby a detecting sugar scoop defect.