Sheet counting method and apparatus
AssigneeDe La Rue Systems Limited
InventorChristopher A. P. Phillips
Life of this patent
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Abstract
A method of countng a succession of sheets passing along a flow line (the sheets being normally spaced but including some overlapping sheets), comprises determining the position of a double thickness in relation to the total length of the sheet in the flow direction. A count of two is added to the count of sheets if the double thickness is found to be symmetrically placed in relation to the total length of the sensed "sheet" and has a length consistent with the amount by which two single sheets would have to overlap to have a total length equal to the sensed "sheet" length. If these requirements are not met, depending on the results of the measurements either a count of one is added or an error signal is generated.
Claims10
A method of counting sheets of given length and of a given thickness in a succession of spaced single sheets and overlapping sheet combinations passing along a flow-line, comprising the steps of:
- sensing the beginning and end of a sheet, or combination of overlapping sheets, travelling along the flow-line to ascertain a sensed length therefor;
- detecting any increased thickness in the sensed sheet or sheet combination and storing the positions of the beginning and end of such increased thickness in relation to the sensed length of the sheet or sheet combination under evaluation;
- automatically testing to ascertain whether a detected increased thickness is substantially symmetrically placed about the mid-point of the sensed length in the direction of the flow-line and has a length not substantially less than the amount by which two sheets of the given sheet length would have to overlap to have a total length equal to the said sensed length;
- and adding two to the count of sheets if the result of the said test is positive.
A sheet counting machine for counting sheets of a given length and of a given thickness in a succession of spaced single sheets and overlapping sheet combinations passing along a flow line, comprising:
- means for sensing the beginning and end of a sheet or combination of overlapping sheets passing along a flow line to ascertain a sensed length therefor;
- means for detecting portions of the sheet or overlapping sheet combination which have a thickness greater than that of a single sheet and for storing the position of the portion of greater thickness in relation to the said sensed length of the sheet or overlapping sheet combination;
- means for testing whether a detected increased thickness is substantially symmetrically placed about the mid-point of the sensed length in the direction of the flow line and is of a length not substantially less than the amount by which two sheets of the given sheet length would have to overlap to have a total length equal to the said sensed length;
- and means for adding two to the count of sheets in responsed to a positive output from the said testing means.
Dependencies are inferred from the claim text.