Packing machine with adjustable means for weakening selected portions of cardboard blanks or the like

In a packing machine wherein commodities are draped into blanks having weakened portions constituting fold lines for conversion of such blanks into envelopes for the respective commodities, the combination of means for transporting a succession of blanks in a predetermined direction along a predetermined path;

• a packing station adjacent to a first portion of said path;
• means for feeding commodities of varying dimensions to said first portion of said path;
• a blank treating unit adjacent to a second portion of said path ahead of said first portion, as considered in said direction, said unit comprising blank weakening means including a pair of tools, means for moving said tools at least once toward and away from said path into and from engagement with successive balnks on advancement of such blanks into said second portion of said path, support means for said tools, said tools being movable with reference to said support means between a plurality of different positions relative to said second portion of said path so that the tools can engage and weaken different portions of a blank in each of said different positions thereof, means for moving said tools between said different positions including reversible prime mover means and means for moving said tools nearer to and further away from each other in response to actuation of said prime mover means, and first and second guide means on said support means, one for each of said tools, said tools being movable in the respective guide means toward and away from the blanks in said second portion of said path;
• means for monitoring the dimensions of commodities which are about to be draped into blanks in said first portion of said path, including means for generating signals which denote the height of commodities;
• means for actuating said prime mover means in response to said signals to that the selected distance between said tools is a function of the height of monitored commodities;
• and means for moving said monitoring means between a plurality of different positions in response to actuation of said prime mover means so that each position of said tools corresponds to a different position of said monitoring means, including a mobile carrier for said monitoring means, a feed screw meshing with said carrier and means for transmitting torque from said prime mover means to said feed screw.