Patent ID: 7669509

Claim:
A guillotine cutter comprising: a sheet bundle supporting table fixed to a frame; a guillotine cutter blade extending along one linear side edge of said sheet bundle supporting table and arranged for vertical movement; a pressing block for pressing a sheet bundle supported on said sheet bundle supporting table against said sheet bundle supporting table; a pressing block driving mechanism supporting said pressing block for vertical movement and positioning said pressing block at a standby position at which said pressing block is spaced upwardly from said sheet bundle, at a first operating position at which said pressing block presses said sheet bundle by a first pressing force, and at a second operating position at which said pressing block presses said sheet bundle by a second pressing force, said second pressing force being larger than said first pressing force; a driving means; and a controller; characterized in that said pressing block driving mechanism comprises at least one rod arranged for vertical movement along its axial direction; said rod and said pressing block being coupled to each other in such a manner that said rod can move in its axial direction with respect to said pressing block, said rod being provided with an expansion portion at a first portion extending upwardly from said pressing block, said expansion portion being capable of engaging with an upper end surface of said pressing block, and that said pressing block driving mechanism further comprises a compression spring for upwardly biasing said pressing block fixed to a second portion of said rod at its lower end, said second portion extending downwardly from said pressing block, said compression spring abutting on said pressing block at its upper end, said driving means being connected to said rod so as to vertically move said rod and said pressing block, said controller controlling said driving means in such a manner that said pressing block is sequentially moved down from said standby position to said second operating position through said first operating position, whereby said pressing block is supported by said rod through said compression spring at said standby position, said pressing block is supported on an upper surface of said sheet bundle at said first operating position in such a manner that said pressing block applies said first pressing force to said sheet bundle composed of a resultant force of a gravitational force generated by its own weight and a biasing force generated by said compression spring, and said pressing block is pushed down by the expansion portion of said rod while said pressing block is kept being supported on the upper surface of said sheet bundle at said second operating position in such a manner that said pressing block applies said second pressing force to said sheet bundle composed of a resultant force of said first pressing force and the push-down force generated by said rod.