cylinder so that a tool can be inserted in the grooves to operate the set screws to urge the cutting rule and mounting bar against opposite walls of the slot to engage the cutting rule in the slot application_number US 87961786 A description a first embodiment of a rotary cutting cylinder constructed according to the principles of this invention indicated generally as 20 in fig1 is shown in fig1 7 cutting cylinder 20 has left and right ends 22 and 24 for mounting cylinder 20 in a machine cutting cylinder 20 has a central section 26 of enlarged diameter a number of grooves 28 are longitudinally spaced along central section 26 of cutting cylinder 20 these grooves 28 preferably extend completely around the circumference of cutting cylinder 20 so that cutting cylinder 20 including grooves 28 can be conveniently formed on a lathe in one operation however as shown in the other embodiments described below partial grooves tangential cuts or notches can be u sed instead of grooves 28 drive rolls 30 and 32 can be press fit onto cutting cylinder 20 at opposite ends of central section 26 a longitudinal slot 34 is formed in cutting cylinder 20 crossing grooves 28 slot 34 is wide enough to accommodate a cutting rule 36 a shim 38 and a mounting bar 40 cutting rule 36 has a beveled cutting edge 42 protruding sufficiently from the profile of central section 26 to cut for example a web material pressed against it shim 38 helps to fill slot 34 and stiffen cutting rule 36 and prevent it from warping mounting.