Sheet transfer apparatus for rotary printing presses
AssigneeHeidelberger Druckmaschinen Aktiegesellschaft
InventorWilli Jeschke
Life of this patent
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Abstract
A sheet transfer system on a rotary printing press has an apparatus provided beneath the delivered sheets to slow down the sheets at their trailing end by means of conveyor belts which are guided by drive and deflector rollers, and between which, beneath the conveyor belt, there is a suction chamber, whereby even with a tight sheet sequence and high machine speed, a collison of the sheets during the deceleration process is prevented so that the sheets are slowed down and lowered onto the sheet delivery stack.
Claims12
A sheet transfer apparatus for a rotary printing press for decelerating printed sheets, said sheet transfer apparatus comprising:
- a first and a second roller having a conveyor belt connected therebetween;
- said conveyor belt having an uppermost surface, in use, for receiving and decelerating sheets from sheet delivery means;
- vacuum means being disposed beneath and supplying vacuum to said uppermost surface, in use, of said conveyor belt;
- said conveyor belt having means for passing the vacuum from said vacuum means therethrough to hold a sheet disposed thereabove;
- first crank means being attached to said first roller for moving said first roller in a first path;
- second crank means being attached to said second roller for moving said second roller in a second path;
- means for synchronizing movement of said first and second crank means with a trailing edge of a sheet being received from sheet delivery means at an upper position of at least one of said cranks;
- and
- means for releasing a held and decelerated sheet at a position of at least one of said cranks lower than said upper position whereby a released sheet is lowered to a sheet delivery stack.
In a printing press, a sheet transfer device comprising:
- conveyor belt means having at least a portion of a top surface for making contact at given portions of a sheet being transferred from sheet delivery means;
- suction-producing means disposed below and in the vicinity of the portion of said top surface of said conveyor belt means for making contact with a sheet;
- said conveyor belt means having means for transferring vacuum from said suction-producing means to a sheet being transferred by and being disposed on said conveyor belt means, said vacuum transferring means for transferring the vacuum to a top surface of said conveyor belt means for holding said given portions of said sheet on said conveyor belt means and for slowing said sheet down when held on said top surface;
- and
- means for moving at least said top surface of said conveyor belt means up and down and for lowering at least the portions of said top surface, for contacting portions of a sheet, from a substantially horizontal position for receiving a sheet from said sheet delivery means to a substantially horizontal position for transferring a sheet to a delivery pile for having sheets stacked one above the other;
- and
- said suction-producing means having a source for producing vacuum for at least a time when a portion of a sheet is in contact with said top surface of said conveyor belt means.
Dependencies are inferred from the claim text.