A paper-transport mechanism using tapered rubber rollers to generate cross-directional tractive force

Abstract

A paper transport mechanism that generates tractive force in the cross direction perpendicular to the paper transport direction was developed. The mechanics of this mechanism were then investigated by using the finite element method (FEM). A pair of tapered rubber rollers is the key point of the mechanism. Each roller has two tapered surfaces that thin out in the same direction. The thin sides of both tapered rollers face each other symmetrically to form the center of the transport mechanism. A cylindrical steel roller is pressed toward the tapered roller by a spring. Paper sheets are nipped between the tapered rubber roller and the cylindrical steel roller. On being pressed, the tapered roller is bent around the mid point of the side of the roller because of it has an asymmetrical cross section. The bend first produces shear stress on the contacting area perpendicular to the transport direction. Second, it produces a bulgy deformation so the roller shape is pressed out in the same direction. These processes generate tractive force on the paper. However, the tapered roller generates not only a tractive force but also a twisting moment. Therefore, one roller has two tapered surfaces to cancel the twisting moment. FEM analysis indicates that the tractive force could be estimated within 20% error in comparison with the measured value. The advantages of the new mechanism are that rubber rollers are used in almost all paper-handling equipment and simply cutting two tapers can generate tractive force. This mechanism improves transport reliability preventing wrinkles and slack. IntroductionA rubber roller is one of the most important components in paper-handling equipment. Its design is closely related to transport performance, namely, precision, feeding forces and so on. Soong et al. [1] and Okamoto et al. [2] studied the behavior of rubber rollers in the transport direction. They clarified the transport mechanics by analyzing the stress distribution in the transport direction and the effect of the mechanical characteristics of rubber on transport precision.Moreover, flattening the papers so that no wrinkles or slack occurs in the cross direction (perpendicular to the transport direction) is required to prevent paper jams and poor printing quality. To meet this demand, we identified the transport mechanisms that generate tractive force in the cross direction and developed a mechanism that uses double-tapered rubber rollers. This mechanism is easily applicable to real products because it has a simple structure and good durability.We clarified the mechanics regarding the tractive force by using a finite-element method (FEM) to analyze the behavior of the tapered rubber roller. And we experimentally confirmed that the FEM could precisely estimate the tractive force. Concept of a tapered rollerAs illustrated in Fig. 1, in a typical paper transport mechanism that uses rollers, paper is nipped between the drive rubber rollers and driven rollers, which are pressed by springs. The rubber rollers and the paper contact during ro...

Technologies for developing an advanced intelligent ATM with self-defence capabilities

“…Next, the features are detected, and the feature template matching is done based on local pattern perturbation to absorb local distortion caused by fluctuations in corrections of the alignment and the normalisation and in transport speed as the note moves through the machine. Damaged banknote detection: The detection of torn banknotes 8,9 is important for maintaining the quality of banknotes in circulation and to protect against mechanism jamming. An example torn banknote is shown in Figure 6 (a).…”