GB2242415A

GB2242415A - Sheet separator with sheet restraining means.

Info

Publication number: GB2242415A
Application number: GB9104369A
Authority: GB
Inventors: Guy Chevrolier; Jean Michel Ciccone
Original assignee: Sagem SA
Current assignee: Sagem SA
Priority date: 1990-03-02
Filing date: 1991-03-01
Publication date: 1991-10-02
Also published as: FR2659071B1; GB9104369D0; EP0445029A1; DE69114030D1; EP0445029B1; DE69114030T2; FR2659071A1; ES2079593T3

Description

APPARATUS FOR SUPPLYING PAPER The present invention relates to an

apparatus for supplying a machine with a succession of sheets of paper arranged in a stack, comprising means for receiving the stack and means for separating each 5 of the sheets from the tack.

Such an apparatus is used in particular for office machines such as printers, photocopiers and facsimile machines, for example, the sheets of paper being either blank or already printed.

Apparatus of the type described above are already known, but the latter are complicated and bulky and require a motor for conveying the sheets to the outlet of the receiving means, owing to the fact that the latter in general comprise a tray disposed horizontally.

Such an apparatus is also known from the document CH-A-538 985, in which:

the means for receiving the stack are arranged in order that the latter is in an inclined position in order to be entrained, under the effect of its own weight, towards the separation means, and, these separation means comprise entrainment means cooperating by friction with the free side of one of the two end sheets of the stack, and, along the path of the sheets thus entrained, a flexible blade, pressed against said entrainment a rigid pres;ure sole plate in order by friction, the sheets other than that with the entrainment means.

means by to retain, cooperating In such an apparatus, it is not necessary to provide a specific motor for loading. In addition, the provision of the separation means directly at 1 1 the outlet of the receiving means gives the apparatus a compact structure, thus reducing its bulk. In addition,-the separation of the sheets from a stack of blank sheets is carried out automatically.

However, in such an apparatus, it is not possible to ensure a constant and reproducible pressure of the flexible blade on the sheets, without imposing severe manufacturing tolerances.

The present invention intends to obviate this drawback.

To this end, it relates to an apparatus of the type described above, characterised by the fact that the pressure sole plate is mounted to move with two degrees of freedom corresponding to two rotations, one about an axis parallel to the path of the sheets, the other about an axis perpendicular to ti-As path.

Appropriate centering of the tilting pressure sole plate thus occurs automatically, which thus ensures a constant and reproducible pressure on the sheets.

Advantageously, the said pressure sole plate comprises two projecting edges perpendicular to the path of the sheets, in contact with said flexible blade.

Thus, the pressure on the sheets occurs in the areas imposed by the projecting edges, and it is thus controlled better.

In a first embodiment, the said pressure sole plate is provided with two wings giving it the shape of a stirrup and it is connected, through the inter- mediary of a joint of the. "universal" type, to an - 3 embedded resilient blade for applying pressure.

Such an apparatus is particularly simple to produce and assemble.

In a second embodiment, the said pressure sole plate is placed under pressure by at least one spring bearing on a fixed support and the position of the spring is adjustable in order to distribute.the pressure.

The apparatus may thus be adapted to different types of sheets of paper.

Advantageously, a central stop is provided for limiting the amplitude of movement of the said sole plate in the direction perpendicular to the plane of the sheets as they travel.

This feature makes it possible to prevent the penetration of too large a pile of sheets, the sole plate thus coming, under the effect of the thrust which is exerted on the side of the pile of sheets, to tilt against the central stop, which has the effect of preventing the passage of the pile from the opposite side. The apparatus is self-locking, since the blocking is all the more effective the higher the number of sheets introduced.

Advantageously, resilient means are provided for pressing the sheets against the entrainment means.

In this case, the frictional force under the action of which the sheet is entrained, is constant.

This results in particular in a regular movement of the sheet entrained.

Still advantageously, the entrainment means comprise a roller set in rotation about its axis, the first generatrix of said roller in contact with said flexible blade is disposed after the resilient pressing means along the path of the sheets and the distance between the two is seen, from the axis of the roller at an angle comprised between substantially 10 degrees and substantially 30 degrees.

These features further improve the efficiency of the flexible retaining blade, as will be understood better hereafter.

In the preferred embodiment, the friction surface of the entrainment means is made from a material whereof the coefficient of friction relative to the paper is greater than substantially unity and the flexible retaining blade is made from a material whereof the coefficient of friction relative to the paper is less than substantially unity and the dimension, in a direction perpendicular to that of the path of the sheets, of the frictional surface of the retaining means is appreciably less than that of the frictional surface of the entrainment means, in the same direction.

Advantageously, the entrainment means comprise a roller tangential along one of its generatrices with the end sheet with which they cooperate and the flexible blade is arranged in order to form an angle with the sheets of the stack other than that cooperating with the drive means.

This embodiment is particularly simple, reliable and has a low cost price.

The present invention will i be better understood on reading the following description of two preferred embodiments of the apparatus of the invention, made with reference to the accompanying drawings, in which:

Figure 1 is a simplified side view, in section, of an apparatus for supplying an office machine with sheets of paper, Figure 2 is a simplified front view of the apparatus of Figure 1, Figure 3 is a simplified front view, in section, of 10 the pressure sole plate of the apparatus of Figure 1 ' Figure 4 is a view of the apparatus of Figure operation, and 1 during Figure 5 is a view of a variation of the apparatus of Figure 1 With reference to Figures 1 to 3, an apparatus for supplying an office machine, in this case a facsimile machine, with a succession of sheets of paper arranged in a stack is now described.

The apparatus comprises a tray for receiving the stack 2 of sheets of paper, whereof the base 1 is inclined with respect to the horizontal, in order that the stack 2 is entrained, under the effect of its own weight, from the side of the lower horizontal edge 11 of the tray 1.

Disposed along this edge 11 is an arrangement intended to separate each of the sheets from the stack 2. This arrangement comprises in particular a roller 3 which is circular and has its axis parallel to the edge 11, in this case arranged in order that the lowest sheet 21 of the stack 2 is substantially tangential i - 6 with the surface of the roller 3.

The surface of the roller 3 is in this case made from rubber having a hardness less than substantially 30 shores A, and its coefficient of friction with respect to the paper is of the order of 1.2. The dimension of the roller 3 along its axis is at least of the order of magnitude of the dimension of the sheets in the same direction. The cylinder 3 is set in rotation about its axis by a motor and a suitable drive mechanism, in the direction indicated by the arrow 33, which corresponds to the entrainment by friction of the sheet 21 from the tray.

Metal blades 32, of which there are two in this case, resiliently press the sheets of the stack 2 against the roller 3. The blades 32 each extend in a plane forming an acute angle oC with the plane of the base 1 of the tray and their ends press the sheets of the stack 2 at points situated substantially on the generatrix T of tangency between the roller 3 and the sheet 21. In this case the blades 32 have curved ends, in particular so as not to damage the sheets, or, in the absence of sheets, the surface of the roller 3.

The blades 32 are fixed to the upper part 12 of the receiving tray, which forms with the base 1 an angle less than the angle Cr-, thus contributing to separating the sheets from the stack 2.

A rubber blade 4, in this case having a hardness of the order of 60 shores A and a coefficient of friction with respect to the paper of equal to 0.9, is mounted in a fixed manner to bear against the roller 3. The area of contact between the blade 4 and the roller i t J i T;' 1 i 3 extends along the path of the sheet 21 when the latter is entrained by the roller 3. In this case, the blade 4 is fixed in order that its face directed towards the roller 3 extends, in its upper part, in the same plane as the blades 32. However, owing to the fact that the rubber blade 4 is longer than the metal blades 32 and owing to its different flexibility, it bends in order that the area over which it is in contact with the roller 3, defined by one generatrix of the roller 3, or generatrix of contact, marked C in Figure 1, is disposed after the generatrix T on the path of the sheets and at a distance from the latter. In this case, the angle)6 at which the portion of the roller 3 comprised between the generatrices C and T is seen, of the order of 15 comprised between substantially 10 degrees and substantially 30 degrees.

from the axis of the roller 3, is degrees. The angle P couldbe The flexible blade 4 is pressed against the roller 3 by a pressure sole plate 5 which is rigid and mounted to move with two degrees of freedom, in order that the flexible blade 4 follows the shape of the roller 3 beyond the generatrix of contact C.

As is apparent from Figure 3, the pressure sole is provided with two wings 53 and 54, which stirrup. Each of the plate give it the shape of a wings 53 and 54 is provided with an oblong aperture in which engages one end 551 and 552 respectively of a shaft parallel with the axis of the roller 3. The shaft 55 comprises a rounded enlarged part 553 which comes to bear against the sole plate 5 itself. The shaft is connected to an embedded resilient blade 6 for applying pressure, which thus presses the sole plate against the blade 4.

i 1 1 The sole plate 5 is thus able. to rotate about the shaft 55 perpendicular to the path of the sheets, and, -by virtue of the oblong apertures in its wings 53 and 54, about an axis parallel to this path. Each of these rotations corresponds to one degree of freedom, the arrangement which has been described forming a joint of the "universal" type between the sole. plate 5 and the embedded resilient blade 6.

The sole plate 5 also comprises two edges 51 and 52, parallel to the axis of the roller 3, and thus perpendicular to the path of the sheets, in contact with the flexible blade 4.

As shown in Figure 2, in which the sole plate 5 has not been shown for the sake of simplicity of the drawings, the dimension of the blade 4, along the axis of the roller 3, i.e. perpendicular to the path of the sheets, is substantially less than that of the roller 3 and the blade 4 extends in the central part of the roller 3, the blades 32 in this case being disposed on either side of the blade 4.

The apparatus which has been described operates as follows.

When the roller 3 is set in rotation about its axis in the direction of arrow 33, the lowest sheet 21 of the stack is entrained by the friction of its free lower side with the roller 3, owing to the fact that it is pressed by the metal blades 32 against this roller 3.

If the sheet 21 slides without difficulty against the sheet of the stack immediately above, it is the only one to be entrained. However, it frequently i 1 1 1 1 1 f happens that the sheet 21 entrains with it one or more sheets of the stack, in particular owing to the fact that the coefficient of friction between the various sheets of paper is too high, or even to the fact that the sheets remain attached to each other by the roughness of their edges.

Such a situation, where several sheets of the stack 2 are entrained, is illustrated. in Figure 4, where it is apparent that the rubber blade 4, disposed on the path of the sheets thus entrained, retains the sheets other than the sheet 21 which cooperates with the roller 3. The blade 4 retains the sheets for two reasons. On the one hand, the sheets other than the sheet 21 form with the blade 4 an angle marked Y, which means that they have a tendency to remain blocked to the On the located in the roller 3 blade 4.

against the blade 4.

This is due.in particular stagger between the generatrices T and C. other hand, if despite everything, the sheet immediately above the sheet 21 is entrained area of contact between the blade 4 and the it will be retained, by friction, by the In fact, in the case where solely the sheet 21 is entrained between the blade 4 and the roller 3, the frictional force between the blade 4 and the sheet 21 is less than that between the roller 3 and the sheet 21, which results in the entrainment of the sheet 21. However, the frictional force of the blade 4 is sufficient to retain, by friction, any sheet other than that which cooperates with the roller 3.

Thus, the separation of each of the sheets from the stack 2 is ensured by the cooperation of the roller 3, which directly entrains a single sheet, and of the blade 4 which retains the sheets other than that directly entrained, but which could nevertheless be entrained indirectly.

Owing to its two degrees of freedom, the pressure sole plate 5 is placed automatically in position and ensures constant pressure.

Figure 5 shows a variation of the apparatus of Figure 1, in which the same parts bear the same reference numerals. The apparatus of Figure 5 differs essentially from that of Figure 1 by the shape and assembly of the sole plate. The sole plate 5' of Figure 5 is provided withprojecting edges 51' and 52', in this case rounder than the edges 51 and 52 and with clips 53' each comprising an oblong aperture which cooperates with a fixed shaft integral with a rigid support 8.

one or more springs 61, in this case coil springs, are disposed between the support 8 and the sole plate 5' for the application of pressure. The position of the line of action D of the springs 61 is adjustable, by virtue of lugs which are not shown for the sake of simplicity of the drawings, cooperating with each of the ends of the springs 61. The sole plate 5' is thus, like the sole plate 5, able to move about two perpendicular axes and the distribution of the pressure between the edges 51' and 52' can be altered by changing the position of the springs 6'. In order to prevent the engagement of too large a pile of sheets, an adjustable stop is provided, in this case a simple screw 9, cooperating with a threaded hole in the support 8 and which limits the amplitude of the movement of the sole plate 51 in the direction perpendicular to the plane of the sheets as they travel. In addition, the screw 9 is in a central position with respect to the sole plate 51, in order that when the sole plate 5' is in abutment against the screw 9, the lifting of the edge 52' by the pile of sheets 2 causes the i 1 11 tilting of the sole plati 51 about its point of contact with the screw 9, in order to move the edge 511 closer to the roller 3 and thus prevent the passage of the pile of sheets below the flexible blade 4.

Naturally, the present invention is not limited to the embodiment which has been described and it is within the scope of a man skilled in the art to determine, for the roller 3 and the blade 4, materials other than those which have been described, by combining the frictional forces in order to achieve the desired result. Good results are obtained when the coefficient of friction of the blade 4 with respect to the paper is less than unity, that of the roller 3 with respect to the paper being greater than unity.

is Furthermore, it would be possible to provide, instead of the entrainment of the sheet of the stack disposed at its lower end, an entrainment of the sheet disposed at the upper end of the stack, by friction with its free side, which would thus be the upper side of the sheet

Claims

1. Apparatus for supplying a machine with a succession of sheets of paper arranged in a stack (2), comprising means (1) for receiving the stack and means (3, 4) for separating each of the sheets from the stack (2), an apparatus in which:

the means (1) for receiving the stack (2) are arranged in order that the latter is located in an inclined position in order to be entrained, under the action of its own weight, (3, 4), and towards the separation means the separation means comprise entrainment means (3) cooperating by friction with the free side of one (21) of the two end sheets of the stack (2), and, along the path of the sheets thus entrained, a flexible blade (4), pressed against said entrainment means (3) by a rigid, pressure sole plate (5; 51) for retaining, by friction, the sheets other than that (21) cooperating with the entrainment means (3)r characterised by the fact that the pressure sole plate is mounted to move with two degrees of freedom corresponding to two rotations, one about an axis parallel to the path of the sheets, the other about an axis perpendicular to this path.

2. Apparatus according to Claim 1, in which said pressure sole plate (5; 51) comprises two projecting edges (51, 52; 511, 52') perpendicular to the path of the sheets, in contact with said flexible blade (4).

3. Apparatus according to one of Claims 1 and 2, in which said pressure sole plate (5) is provided - 1 1 1 i I i 1 i 1 i i i t 1 13 - with two wings (53, 54) giving it the shape of a stirrup, and it is connected, through the intermediary of a joint of the universal type, to an embedded resilient blade (6) for applying pressure.

4. Apparatus according to one of Claims 1 and 2 in which said pressure P-)1e plate (5 by at least one sprina support (8) and the p.

) is pressed into abutment with a fixed in of the spring (61) is adjustable in order to distribute the pressure.

5. Apparatus accordinq to one of Claims 1 to 4, in which a central stop (9) is provided for limiting the amplitude of the movement of said sole plate (5 in the direction perpendicular to the plane of sheets, as they travel.

is

6. Apparatus according to one of Claims 1 to 5, in which resilient means (32) are provided for pressing the sheets against the entrainment means (3).

7. Apparatus according to one of Claims 1 to 6, in which the entrainment means comprise a roller (3) set in rotation about its axis, the first generatrix (C) of said roller (3) in contact with said flexible blade (4) is disposed after the resilient pressing means (32) on the path of the sheets, and the distance between the two is seen, from the axis of the roller (3), at an angle( 13)comprised between substantially 10 degrees and substantially 30 degrees.

8. Apparatus according to one of Claims 1 to 7, in which the entrainment means comprise a roller (3) tangential along one of its generatrices (T) with the end sheet (21) with which they cooperate.

1 1 11 14 -

9. Apparatus according to one of Claims 1 to 8, in which said flexible blade (4) is disposed in order to form an angle ( 2r) with the sheets of the stack (2) other than that (21) cooperating with the entrainment means (3) 1 1 i Published 1991 at The Patent Office- Concept House. Cardiff Road. Newport. Gwent NP9 I RH. Further copies maybe obtained from Sales Branch. Unit 6. Nine Mile Point. Cw7nfelinfach. Crosi Keys. Newport. NPI 7HZ. Printed by Multiplex techniques ltd. St Mary Cray. Kent.