| 摘要 |
An apparatus for testing the stiffness of a sheet, such as a currency note, includes first cooperating rollers (36, 38) and second cooperating rollers (28, 32) arranged to urge the sheet along a feed path (48). The first rollers (36, 38) engage frictionally with the sheet and are caused to rotate with a greater peripheral speed than the second rollers (28, 32). As a result, there is a tendency for the first rollers (36, 38) to cause that portion of the sheet between the first and second rollers (36, 38; 28, 32) to buckle, this tendency being resisted if the sheet has a required degree of stiffness. First and second sensors (66, 68) are disposed on opposite sides of said feed path (48) for sensing a deflection of said portion of said sheet away from the feed path (48) by at least a predetermined amount, brought about by buckling of the sheet due to the sheet being insufficiently stiff. <IMAGE> |
