Patent ID: 6205899
Filing Date: 2001-03-27
Classification: B26D,B26F,Y10S,Y10T

Abstract:
A rotatable knife roll for cutting out window openings in envelopes, comprising:a roll body having two face sides;at least one foil knife disposed on a part of the roll body and having a sharp and endless cutting edge closed within itself;a plurality of breakthroughs within said cutting edge;at least one suction-air control valve arranged on at least one face side of the roll body and being rotatable relative to said roll body, said suction-air control valve comprising:(a) at least one suction-air-control channel; and(b) at least one fresh-air channel;a plurality of suction apertures disposed on the knife roll, some of said apertures being connected to the breakthroughs, for temporarily retaining a letter envelope blank over a suction and transport angle zone .alpha., and for retaining a piece of material cut out by the foil knife across a suction and transport angle zone .beta., said suction apertures being arranged in rows to which said suction and fresh air channels are allocated,at least one suction channel connected with the suction apertures and with the suction air control channel and fresh air channel, for conducting air between the suction-air control channel and the fresh-air channel and the suction apertures; anda 3/3-way valve associated with the suction channel upstream of the suction-air control valve, said 3/3-way valve having an open position for each of suction and transport angle zones .alpha. and .beta., and one common closing position for suction and transport angle zones .alpha. and .beta..