Patent ID: 8248443

Claim:
A laser marking unit ( 1 ) for marking packets ( 2 ), comprising: a marking conveyor ( 6 ) for feeding the packets ( 2 ) successively along a marking path (P); and a marking station ( 16 ) located along the marking conveyor ( 6 ), and comprising a laser marking device ( 17 ) for marking a code on the outer surface of each packet ( 2 ) conveyed on the marking conveyor ( 6 ); wherein the laser marking device ( 17 ) comprises a laser beam generator ( 18 ) which emits a laser beam by means of an emitter ( 19 ); and a deflection box ( 20 ) which deflects the laser beam onto the packet ( 2 ) at the marking station ( 16 ) by directing the laser beam along a focusing path ( 23 ) that starts at the emitter ( 19 ) and terminates on the outer surface of the packet ( 2 ); wherein the deflection box ( 20 ) is mechanically connected removably, and therefore replaceably, to the generator ( 18 ); wherein at least two different, interchangeable deflection boxes ( 20 a , 20 b ) are provided; wherein in both deflection boxes ( 20 a , 20 b ), the corresponding focusing paths ( 23 ) are exactly the same length, which equals a focal length of the laser beam generator ( 18 ); and wherein a first deflection box ( 20 a ) marks the progressive code on an end wall ( 28 ) of a packet ( 2 ) fed through the marking station ( 16 ) on the marking conveyor ( 6 ), and a second deflection box ( 20 b ) marks the progressive code on a lateral wall ( 29 ) of a packet ( 2 ) fed through the marking station ( 16 ) on the marking conveyor ( 6 ).