GB2035268A

GB2035268A - Separating sheets from piles

Info

Publication number: GB2035268A
Application number: GB7845415A
Authority: GB
Original assignee: Laurel Bank Machine Co Ltd
Current assignee: Laurel Bank Machine Co Ltd
Priority date: 1978-11-21
Filing date: 1978-11-21
Publication date: 1980-06-18
Also published as: GB2035268B

Abstract

A roller system for separating sheets from a pile consists of a feed roller 11 and a return roller 12 which rotate in the same sense. Sheets of paper are drawn from a pile one by one by the feed roller 11 and passed through the gap between the rollers, the sheet being driven by the greater frictional force applied by the feed roller than by the return roller. The rollers each have frictional surfaces 14, 15 of the same material or of material having the same or substantially the same coefficient of friction with respect to the sheets, and the axial extent of the frictional surface of the feed roller is larger than the axial extent of the frictional surface of the return roller. Thus, the dimension B is less than 2A. <IMAGE>

Description

SPECIFICATION A roller system for delivering sheets The present invention relates to a roller system for delivering sheets particularly of paper one by one.

For example, it may be required to deliver, one by one, bank notes from a horizontal bundle. A known system which is suitable is shown in Figures 1 and 2.

In the drawings, reference numerals 1 and 2 represent a feed roller and a return roller, respectively. Rotation shafts la and 2a of these rollers 1 and 2 are arranged parallel to each other in the delivery zone so that the peripheral surfaces of both the rollers 1 and 2 are brought close to each other (with a gap or nip corresponding to the thickness of one sheet of paper). Reference numeral 3 represents a horizontal stack of sheets of paper which is pressed against the feed roller 1 in the delivery zone by suitable application of force to the paper sheets so that the lower end of the outermost sheet of paper 3a bears against the peripheral surface of the roller 1.

Both the rollers 1 and 2 are rotated in the same sense. Namely, the feed roller 1 is rotated in a direction rolling up and delivering the outermost sheet of paper and the return roller 2 is rotated in a direction returning the sheet of paper. Accordingly, the outermost sheet 3a which is in contact with the peripheral face of the feed roller 1 is passed between both the rollers 1 and 2, but since the second and subsequent sheets of paper do not come into contact with the feed roller 1, the lower end portions of these sheets are subjected to only the returning force of the return roller 2 and they are not rolled up in between the two rollers 1 and 2. As shown in Figure 2, the rollers 1 and 2 have on their peripheries frictional surfaces 4 and 5 composed of materials which have different coefficients of friction.A frictional force in the delivery direction is imposed on the upper face of the sheet of paper 3a gripped between the rollers 1 and 2 and a frictional force in the return direction is imposed on the lower face of the sheet of paper 3a. However, since the frictional force imparted by the feed roller 1 is larger than the frictional force imparted by the return roller 2, paper sheet 3a is fed out from between the two rollers 1 and 2. After the outermost sheet has thus been fed out, the next sheet of paper comes in contact with the feed rolled 1 and it is rolled up and fed out in the same way. Thus, sheets of paper 3 in the stack are fed out one by one.

in the above described paper delivery system, frictional surfaces 4 and 5 formed on the peripheries of both the rollers 1 and 2 are composed of materials having different coefficients of friction so that there is a difference between the frictional forces applied to the sheet of paper by the two rollers 1 and 2.

According to the present invention there is provided a roller system for delivering sheets one by one from a bundle of sheets which comprises two frictionally tractive rollers, being a feed roller and a return roller respectively, arranged to rotate in the same sense and through the nip of which a sheet of paper can be driven by a greater frictional force from the feed roller than from the return roller, which rollers each have frictional surfaces of the same material or having the same or substantially the same coefficient of friction with respect to the sheets, and the axial extent of the frictional surface of the feed roller being larger than the axial extent of the frictional surface of the return roller at least along the nip.

Another aspect of the invention provides a roller system for delivering sheets of paper comprising a feed roller and a return roller of substantially the same length disposed in a delivery zone so as to form a gap therebetween, said rollers being rotated in the same direction so that frictional forces acting in reverse directions are given to the upper and lower faces of the outermost sheet in a stack of sheets of paper stored in a store zone whereby the sheets of paper stored in the store zone are delivered one by one into the gap between said rollers, said paper delivery roller system being characterized in that said rollers have frictional surfaces of the feed roller with respect to the axial direction thereof is larger than the length of the frictional surfaces of the return roller with respect to the axial direction thereof.

One embodiment of the present invention will now be described by reference to the accompanying drawings where: Figure 1 is a side elevational view showing a known paper delivery system; Figure 2 is a perspective view showing the delivery rollers used in the system shown in Figure 1; Figure 3 is a side elevational view showing one embodiment of the present invention; Figure 4 is a perspective view showing the delivery rollers used in the system shown in Figure 3; and Figure 5 is a front view showing the delivery rollers illustrated in Figure 4.

As shown in Figure 3, sheets of paper 13 are stored in a substantially horizontal stack on a store stand 6 and pressed against a feed roller 11 in the delivery zone by means of a pressing member 8 biased by a spring 7. Accordingly, the lower end of outermost sheet of paper 13a bears against the peripheral surface of the feed roller 11. In the drawing, reference numeral 9 represents a support plate.

The feed roller 11 and return roller 12 are disposed in the delivery zone, and the rotation shafts 1 1a and 12a of both the rollers 11 and 12 are arranged parallel to each other so that the peripheral surfaces of both the rollers 11 and 12 are close to each other with a gap corresponding to the thickness of one sheet of paper 13.

As shown in Figures 4and 5, frictional surfaces 14 and 15 composed of the same material are formed on the peripheries of the feed roller 11 and return roller 12, respectively. The frictional surfaces 14 of the feed roller 11 have a width A, and are positioned at each end of the roller leaving a central portion.

The frictional surface 15 is formed on the centre of the return roller 12 and it has a width B in the axial direction equal to the width of the central portion of the feed roller. The frictional surface 15 of the return roller 12 is located at a position corresponding to the position of the central portion of the peripheral surface of the feed roller 11, where the frictional surface is not present. The total width 2A of the frictional surfaces 14 of the feed roller 11 is larger than the width B of the frictional surface 15 of the return roller 12. Accordingly, the total length of the frictional surfaces 14 in the axial direction is larger than the length of the frictional surface 15 in the axial direction.Formation of such frictional surfaces 14 and 15 on the peripheries of the rollers 11 and 12 may be accomplished, for example, by forming a step on the peripheral surface at a part on which a frictional surface is to be formed and bonding a band-like frictional material to this step. Other methods may of course be used.

The shapes of the frictional surfaces 14 and 15 are not limited to those specifically illustrated in the foregoing embodiment, and any shapes can be adopted providing the length of the frictional surface 14 of the feed roller 11 with respect to the axial direction is larger than the length of the frictional surface of the return roller 12 with respect to the axial direc-tion. Moeover, the method of forming the frictional surfaces is not limited to the method illustrated in the foregoing embodiment, and various other methods may be adopted.

In the roller paper delivery system of the present invention having the above-mentioned structure, among a horizontal stack of sheets of paper stored in the store zone, the outermost sheet of paper alone is introduced between the two rollers 11 and 12 as in the previously described known system, and one surface of this sheet is subjected to the frictional force in the delivery direction by the frictional surfaces 1 4 of the feed roller 11 and at the same time, the other surface of the sheet is subjected to the frictional force given in the return direction by the frictional surface 15 of the return roller 12. Since the sheet of paper is not a rigid body, loads imposed on the sheet of paper gripped between the rollers 11 and 12 are given to the respective parts falling in contact with the frictional surfaces 14 and 15.

Accordingly, although the frictional surfaces 14 and 15 are composed of the same material and they have the same coefficient of friction, since the length of the frictional surfaces 14 of the feed roller 11 with respect to the axial direction is Irger than the length of the frictional surface 15 of the return roller 12 with respect to the axial direction, the friction force given by the frictional face 14 of the feed roller 11 is larger than the frictional force given by the frictional surface 15 of the return roller 12 (the frictional force is equal to the product of the coefficient of frictional and the load). Accordingly, the sheet of paper is delivered from between the rollers 11 and 12.

As will be apparent from the foregoing illustration, the frictional surface of both the feed roller and return roller are composed of the same material and sheets of paper can be delivered by the rollers by appropriately setting the lengths of the frictional surfaces of both the rollers with respect to the axial directions thereof. Still further, in the present invention, an optimum delivery conditions can easily be obtained by appropriately setting the length of the frictional surface of each roller with respect to the axial direction.

Claims

1. A roller system for delivering sheets one by one from a bundle of sheets which comprises two frictionally tractive rollers, being a feed roller and a return roller respectively, arranged to rotate in the sense and through the nip of which a sheet of paper can be driven by a greater frictional force from the feed roller than from the return roller, which rollers each have frictional surfaces of the same material or having the same or substantially the same coefficient of friction with respect to the sheets, and the axial extent of the frictional surface of the feed roller being larger than the axial extent of the frictional surface of the return roller at least along the nip.

2. A roller system for delivering sheets of paper comprising a feed roller and a return roller of substantially the same length disposed in a delivery zone so as to form a gap therebetween, said rollers being rotated in the same direction so that frictional forces acting in reverse directions are given to the upper and lower faces of the outermost sheet in a stack of sheets of paper stored in a store zone whereby the sheets of paper stored in the store zone are delivered one by one into the gap between said rollers, said paper delivery roller system being characterized in that said rollers have frictional surfaces of the same material, thereon respectively and the length of the frictional surfaces of the feed roller with respect to the axial direction thereof is larger than the length of the frictional surfaces of the return roller with respect to the axial direction thereof.

3. A roller system for delivering sheets substantially as hereinbefore described with reference to and as illustrated in Figures 3,4 and 5 of the accompanying drawings.