Device and process for determining the stiffness of sheet-like a

Details Device and process for determining the stiffness of sheet-like a Device and process for determining the stiffness of sheet-like a

1997-09-12

2000-02-22

Williams, Hezron

Measuring and testing

Sheet, woven fabric or fiber

73801, 73587, G01L 504

Patent

active

060266813

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to an apparatus and method for determining the stiffness of sheet material such as bank notes.
2. Discussion of Related Art
Such an apparatus is known from EP-A 0 073 133. In this apparatus the sheet material is guided between two flat belts in the middle and deflected via a double-conical roller by an angle of 180.degree.. Simultaneously the sheet material is deformed in the longitudinal and transverse directions. The sounds produced during this process are detected by a microphone. From the detected sounds an evaluating device determines the stiffness of the sheet material.
A disadvantage of the apparatus is that the produced sounds decrease greatly when the stiffness of a sheet is measured several times. The stiffness of the sheet material lessens with each measuring process due to the deformation involved in the measuring process.
Starting out from this, the invention is based on the problem of proposing an apparatus and method for determining the stiffness of sheet material where the stiffness of the sheet material remains essentially unchanged.


SUMMARY OF THE INVENTION

The basic idea of the invention is essentially to produce sounds by mechanical means which periodically touch the sheet material, causing it to vibrate. The sounds produced by the vibrations are then detected by a detector. From the detected sounds an evaluating device determines the stiffness of the sheet material. Since the volume of the produced sounds is approximately proportional to the stiffness of the sheet material, the volume of the produced sounds is a direct measure of stiffness of the sheet material.
The sheet material is held or guided in a transport device such that it can yield to the mechanical action within certain limits in the area of contact without being irreversibly deformed.
An advantage of the invention is that the stiffness of the sheet material remains virtually unchanged. Even when the stiffness of a sheet is determined several times the intensity of the produced sounds remains essentially the same. The reproducibility of the intensity of the produced sounds is on the average at least 95%.
In a preferred embodiment of the invention the mechanical means have a rotating roll with a certain number of corners. The corners are disposed in rotational symmetry on the roll. The sheet material is transported through the apparatus by a transport device, and the driving axle of the rotating roll is disposed perpendicular to the transport direction of the sheet material. The direction of rotation of the rotating roll is in the direction of transport. The rotary frequency of the rotating roll is selected such that the circumferential speed dependent on the rotary frequency and the radius of the roll is greater than or equal to the transport speed of the sheet material.


BRIEF DESCRIPTION OF THE DRAWINGS

In the following, various embodiments of the invention will be described with reference to the figures, in which:
FIG. 1 shows a schematic diagram of a preferred embodiment,
FIG. 2 shows a schematic diagram of the preferred embodiment with transport belts,
FIG. 3 shows a schematic diagram of the preferred embodiment with transport belts from below,
FIG. 4 shows a schematic diagram of the preferred embodiment with transport belts and a guiding plate from below,
FIG. 5 shows a schematic diagram of a variation of the preferred embodiment,
FIG. 6 shows a schematic diagram of a second embodiment of the invention,
FIG. 7 shows a schematic diagram of a third embodiment of the invention,
FIG. 8 shows a schematic diagram of a fourth embodiment of the invention,
FIG. 9 shows a schematic diagram of a development of the fourth embodiment of the invention,
FIG. 10 shows a schematic diagram of a fifth embodiment of the invention.


DETAILED DESCRIPTION

FIG. 1 shows a schematic diagram of a preferred embodiment of the invention is a side view. Sheet material 10 is transported through the apparatus in direction of transport T for example by means of transp

REFERENCES:
patent: 3894732 (1975-07-01), Muller
patent: 4073007 (1978-02-01), Boivin
patent: 4463607 (1984-08-01), Hilton
patent: 4519249 (1985-05-01), Hunt
patent: 5089776 (1992-02-01), Furukawa et al.
patent: 5201424 (1993-04-01), Hain
patent: 5297062 (1994-03-01), Cresson et al.
patent: 5808199 (1998-09-01), Kazys et al.
patent: 5813277 (1998-09-01), Schmidt et al.

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