Apparatus for stacking continuously arriving sheets

An apparatus for stacking sheets, the apparatus comprising:

• conveyor means having a downstream end spaced upstream in a horizontal transport direction from a stacking station for delivering the sheets continuously one after the other at a predetermined upper level in the direction to the station;
• a main platform vertically displaceable in the stacking station between an upper position below the upper level and a lower position;
• an auxiliary platform below the upper level and formed by a plurality of transversely spaced and parallel rods horizontally displaceable in the direction between an extended position in the station above the main platform, a retracted position upstream of the main platform, and between an upper position just below the upper level and a lower position therebelow;
• a plurality of vertically extending separator elements between the conveyor means downstream end and the stacking station and having bent-over upper ends projecting downstream between the rods in the transport direction and displaceable between
• a separating extended position projecting into the station between the auxiliary platform and the upper level and engaged between trailing edges of the sheets in the station,
• a withdrawn position out of the station between the station and the conveyor means downstream end,
• an upper position with the upper ends just below the upper level, and
• a lower position with the upper ends level with the upper position of the auxiliary platform, each element having a vertical length greater than the vertical distance between the auxiliary platform and the upper level;
• and
• control means connected to the auxiliary platform and separator elements for, when a sufficiently tall stack is formed in the station, sequentially
• raising the elements into their upper positions and advancing the elements into their extended positions,
• lowering the elements into their lower positions while maintaining them in their extended positions to form in the stack a gap level with the auxiliary platform,
• advancing the auxiliary platform into its extended position so as to support the stack above the gap and retracting the elements to their withdrawn positions,
• lowering the main platform, removing the stack therefrom, and raising the main platform to its upper position, and
• withdrawing the auxiliary platform to its retracted position to deposit the stack on it onto the main platform.