| 摘要 |
1. Device for determining the stiffness of a paper article comprising a means to cause a vibration of said paper article to produce a sound, a detector to detect the produced sound and a unit to evaluate sound level, characterized in that said means (30, 34, 40, 50, 60, 70, 80, 81) of paper article vibration (10) represents a unit having a periodical contact with said paper article. 2. Device as claimed in Claim 1 characterized in that said unit having a periodical contact with said paper article comprises rotating polyhedral drum (30, 34) with sides spaced symmetrically towards rotations axis. 3. Device as claimed in Claim 1 characterized in that said unit having a periodical contact with said paper article comprises rotating drum (40) by the perimeter of which brushes are provided spaced symmetrically towards rotations axis. 4. Device as claimed in Claim 2 or 3characterized in that said device is provided with a conveyer system (11, 12) to move said paper article wherein driving axis (31) of said rotating drum (30, 34, 40) is arranged transversely to the direction of feed (T) of said paper article. 5. Device as claimed in Claim 4 characterized in that said conveyer system has the peripheral speed of said drum (30, 34, 40) greater or equal to the speed of a paper article feed wherein a vector of the peripheral speed coincides with the direction of feed (T) of said paper article. 6. Device as claimed in Claim 4 characterized in that said conveyer system comprises upper and/or lower conveyer belts (11, 12), which rest on rollers (32, 33) enabling free rotation on the driving axis (34). 7. Device as claimed in Claim 6 characterized in that said conveyer system comprises a guide plate (13) with a port (14) through which said drum (30, 34, 40) contacts with a paper article. 8. Device as claimed in Claim 1 characterized in that said unit having a periodical contact with said paper article comprises electromagnet (50), which can contact with a paper article via elastic plate (53). 9. Device as claimed in Claim 1 characterized in that said unit having a periodical contact with said paper article comprises piezoelement (60). 10. Device as claimed in Claim 1 characterized in that said unit having a periodical contact with said paper article comprises piezoelement (60), which can contact with a paper article via lever system. 11. Device as claimed in Claim 1 characterized in that said unit having a periodical contact with said paper article comprises electromagnet (50), which can contact with a paper article via movable core. 12. Device as claimed in Claim 1 characterized in that said unit having a periodical contact with said paper article comprises bimorphic piezoelement (60). 13.Method for determining the stiffness of a paper article by producing sound by said paper article, detecting the produced sound, characterized in that the sound is produced after periodic contact with said paper article. |
