| 摘要 |
A method and apparatus for feeding sheets from a top of a sheet stack supported on a stack lifting table to a sheet processing machine. The stack lifting table supporting the sheet stack is raised by a motor until the top of the sheet stack has reached a predetermined maximum level. At this position, the sheets are fed by a feeding mechanism from the sheet stack to the sheet processing machine to lessen the stack height until the top of the sheet stack has reached a predetermined minimum level as determined by a sensor. The rate at which the stack height is lessened as sheets are fed from the stack lifting table is then determined by a controller from the known distance between the predetermined maximum and minimum levels and a value corresponding to the speed at which sheets are fed from the stack. The speed value, or sheet cycle time, may be received from the processing machine, or may be a time duration measured by a timer. The motor is then controllably operated to raise the stack lifting table at a rate corresponding to the rate at which the stack height is lessened, thereby maintaining the top of the stack at substantially the same height as sheets are fed to the sheet processing machine.
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