Blow tube with jet holes

摘要

The holes (9), in the outer blow tube (11), act on the sheet (9) edge region as compared with the inner blow tube (13), enclosed by the outer tube which acts on the central region of the sheet via jet holes (16), supplemented by valves (21,22) which act pneumatically on the inner tube or inner and outer tubes. The outer holes (12) may point outwards at an angle (ALPHA) 10-30 degrees in tube and the holes in the inner tube also pass through the outer tube, the valves allotted respectively to inner and outer tubes. The inner tube should be hermetically sealed relative tube. In service, a stiff printed sheet is exposed to the blow jets from the inner tube nozzles (13,17) as set by the timer valve (21) in the centre of the sheet.