Abstract Master and copy materials are conveyed around the rotating glass cylinder of a printer in the exposure section of a whiteprint duplicating machine, by multiple belts which are driven by a main printer drive roller which advances the belts toward such glass cylinder, and an auxiliary booster drive roller which draws the belts from the cylinder by rotating at a speed slightly higher than that of the main drive roller. The outer surface of the auxiliary drive roller also has a coefficient of friction that is less than that of the main drive roller, so that the auxiliary drive roller continuously slips against the printer belt, but at the same time pulls and evens out the looped belts over the critical printing area of the cylinder.
An improved apparatus for driving multiple belts which convey master and copy materials around the exposure zone of a rotating glass printing cylinder in a white-print duplicating machine, including a main drive roller located beyond said printing cylinder and toward which the belts are advanced by said main drive roller; the improvement comprising an auxiliary booster drive roller located beyond said printing cylinder having a surface with a coefficient of friction less than that of said main drive roller, and means for driving said auxiliary booster roller at a speed greater than that of said main drive roller for continuously taking up any undesirable slack tending to form in the belts as they move on said cylinder through said exposure zone.
Claim 2
Dependent Claim
121 words
An improved apparatus for driving multiple belts which convey master and copy materials around the exposure zone of a rotating glass printing cylinder in a white-print duplicating machine, including a main drive roller located beyond said printing cylinder and toward which the belts are advanced by said main drive roller; the improvement comprising an auxiliary booster drive roller located beyond said printing cylinder having a surface with a coefficient of friction less than that of said main drive roller, and means for driving said auxiliary booster roller at a speed greater than that of said main drive roller for continuously taking up any undesirable slack tending to form in the belts as they move on said cylinder through said exposure zone.
Claim 3
Dependent Claim
54 words
The invention as defined by claim 1, in which the speed of rotation of said auxiliary drive roller is only slightly greater than that of the main drive roller, whereby the belts are continuously lightly tensioned as they move the master and copy materials over the critical printing area of the rotating glass cylinder.