System for automatically coating objects with a plurality of quantities of a coating material using a single discharge apparatus

A system for automatically applying adhesive to the leading and trailing flaps of cartons comprising:

• an adhesive dispensing device coupled to a source of adhesive;
• means for dispensing the adhesive from the dispensing device in response to a control signal;
• means for moving the cartons relative to the dispensing device in a path past the dispensing device;
• a first photosensor positioned along said path and operative to generate a first sensor signal in response to the presence of the leading edge of the leading flap when the carton is at a first point on said path upstream of said dispensing device;
• a second sensor positioned along said path and operative to generate a second sensor signal in response to the trailing edge of the trailing flap of a carton when the carton is at a second point on said path downstream of the first point and upstream of the dispensing device;
• a delay timer responsive to either of the sensor signals to produce a delay signal after a delay time corresponding to a predetermined distance of travel by a carton on the path;
• a duration timer responsive to the delay signal to produce a duration signal for a duration time corresponding to a predetermined distance of travel by a carton on the path, the delay timer and the duration timer being operable to function simultaneously;
• and
• driver means for coupling a control signal to the adhesive dispensing means in response to the duration signal from the duration timer.