EP0672601B1 - Device for feeding sheets or envelopes which are to be printed - Google Patents

Description

The invention relates to a device for introducing flat materials to print, such as sheets of paper and / or envelopes, for printers or write including a substantially flat bottom store in which a stack of said flat materials is disposed and from which these materials are extracted one by one and introduced in the printer, drive rollers arranged on a drive shaft to move the material top of the stack to bring it into the printer or the typewriter, the device further comprising retainers for retaining materials dishes arranged in said stack under the upper flat material and comprising at least one moving part mounted on the store and having a surface intended to enter into contact with the front edge of said flat materials to form a bearing surface with variable orientation for said flat materials, arranged downstream of the rollers drive, the orientation of this bearing surface by report to said substantially planar background being variable in depending on the rigidity of said flat materials to to print.

We know such devices for introducing sheets of paper used in printers, machines to write or in other devices, such as than photocopiers. These devices use very frequently as a retainer for the retaining corners under which the top sheet is extracted when its introduction. If these retaining corners can give satisfaction for use with relatively leaves thin and not very rigid, a use of sheets more thick and rigid or envelopes is no longer possible with this type of retainer.

Document JP-A-58-47739 describes a device having the characteristics appearing in the preamble of the claim 1. In this device, a cassette containing the leaves is provided with a cover leaving a passage for drive rollers. Sheets are used by a spring against the rollers and the cover. The front part is closed by an elastic strip which bends under the push of the upper leaf when the latter is fed by a slot thus created between the cover and the curved elastic strip. he it happens that several sheets pass simultaneously the slit, however the lower leaves are retained by the strip given its high coefficient of friction.

Document FR-A-2 564 455 refers to a device supply with a receptacle containing objects to feed stacked on a base. This receptacle includes a front cover having an opening at its base intended to allow the exit of the lowest driven object by a roller. Two retaining members are arranged at through the opening and formed by rubber fingers likely to retain objects above the one at the base.

The two prior devices thus include elements elastically deformed by the object powered thereby passing through an opening or slot in the cassette or receptacle. However, when the sheet is very thin, its rigidity is not enough to deform the elements and it may be bent to form a plug at the opening. On the other hand, when several leaves are entrained, the leaves frictionally stopped by means of elastic members occupy a more or less advanced position, therefore undefined. They will then be fed irregularly, which can be detrimental for their subsequent use, for example in a printer.

The object of the present invention is to remedy the drawback mentioned above and create a device allowing the introduction of flat materials to print stiffness very different from very thin sheet to paper cardboard or envelopes with a very functioning reliable and precise without even very thin sheets are damaged and without plugging.

The invention is characterized for this purpose by the fact that the retaining members include, associated with said moving part, a fixed inclined plane making a first predetermined angle with a plane parallel to said bottom and substantially extending an anterior wall of the store perpendicular to said bottom, the moving part being mounted on this anterior wall and elastically stressed towards a rest position, in which its bearing surface variable makes a second angle with said parallel plane greater than said predetermined angle of the inclined plane fixed, the moving part being oriented by the flat material so that said second angle of the bearing surface decreases as a function of the increased rigidity of the material dish to introduce, and takes values included between that of said rest position and that of said predetermined angle.

By these characteristics, a very precise operation and reliable is obtained whatever the thickness and the rigidity of the fed flat material. The device works also perfectly without the receptacle being provided with a cover forming with a front wall a opening. Cork formation and damage thin sheets are avoided.

Other advantages emerge from the characteristics expressed in dependent claims and description setting out the invention below in more detail at using drawings which represent schematically and at As an example, an embodiment and variants.

Figure 1 shows a cross-sectional view of the device in the rest position.

Figure 2 is a front view of the device.

Figure 3 shows a side view.

Figures 4a and 4b are partial sectional views transverse of the device when introducing a rigid sheet, respectively not very rigid.

Figures 5 and 6 are partial sectional views transverse of two variants.

The introducer 1 illustrated in Figures 1 to 4 is removably mounted on a printer 2 of which only part of the frame 3 and the introduction channel 4 are represented. The device 1 may of course also be in solidarity or with the printer, the write or any other device using materials dishes, such as sheets of paper, card stock or envelopes. Device 1 includes a magazine 6 with a bottom 8, a front wall 9, two walls fixed side 10 and 11, and a support plate 12 on which a stack of sheets 14, envelopes or all other flat materials can be arranged.

The support plate 12 is pivotally articulated on the side walls 10, 11 by means of two pivots 15 and biased by a spring 16 towards the drive rollers 17, 18 mounted on a drive shaft 20. The latter is connected via a gear train 21 to a motor 22. The magazine 6 further comprises a movable lateral guide 25 slidably mounted according to a lateral direction on the upper part of the support plate 12 to be able to adapt the width of the feeder for different sheet formats or envelopes. The movable lateral guide 25 and the wall side 10 are each provided with guide elements 26, 27 defining an introduction channel for the leaves and facilitating the placement of the stack of sheets 14 in store 6.

Referring to Figures 1, 4a and 4b the anterior wall 9 of the store has an extension 30 comprising a first portion 31 forming a fixed inclined plane making a predetermined angle α with a plane parallel to the bottom 8 of the magazine and a second curved final portion 32 substantially parallel to said bottom 8. This extension 30 further includes three openings 34 and three leaf springs 35 curved at their free ends 36. These leaf springs 35 are arranged along the anterior wall 9 and fixed to the bottom 8 of the magazine 6. Their ends free 36 curved extend inside the openings 34.

In the rest position, as illustrated in Figure 1 and Figure 4B, the non-curved portion 37 of leaf springs 35 makes an angle β greater than the angle α with a plane parallel to the bottom 8. The three leaf springs 35 in combination with the fixed inclined plane 31 constitute thus a retaining member 40 disposed downstream of the rollers 17. The upper surface of the non- curved 37 leaf springs 35 function of surface variable orientation support for sheets or envelopes. The angle β between this bearing surface and a plane parallel to the bottom 8 of the store is variable in depending on the rigidity of the materials to be introduced. This angle β is greater for thin leaves and little rigid where it approaches 90 °, see Figure 4B. By against for rigid sheets, such as card stock or envelopes, the leaf springs 35 serving as bearing surface are strongly pushed down at the Figure 4a by the rigid sheet, so as to obtain a adequate inclination to insert the rigid sheet while retaining the underlying sheets or envelopes. In this case of rigid materials, the angle β becomes equal to the angle α and the extracted rigid sheet slides simultaneously on the fixed inclined plane 31 and on the upper surface leaf springs 35 which are retracted into the openings 34.

The angle α between the fixed inclined plane 31 and a plane parallel to the bottom 8 is preferably chosen between 30 ° and 80 °, very advantageously between 60 ° and 65 °; he is in the configuration illustrated in Figures 1 and 4, 63 °. The inclination of this fixed inclined plane 31 relative to the front wall 9 is therefore between 10 ° and 60 °, and is in Figures 1 and 4 of 27 °.

The variable angle β between the variable bearing surface of the non-curved part 37 of the leaf springs 35 varies therefore substantially between 90 ° and the angle α, namely 63 ° in the case of Figures 1 and 4.

In case the device had only an inclined plane fixed, an angle α should be given relatively low close to 65 ° so that rigid sheets or envelopes can be extracted; otherwise these materials rigid dishes could catch on the plane fixed incline 31. With such a relatively small angle α, thin and not very rigid sheets can no longer be introduced one by one, since the underlying leaves will no longer be sufficiently retained and will be less partially entrained with the upper leaf.

On the contrary with a greater angle α for example of 80 °, the underlying thin sheets will be enough retained, on the other hand the rigid sheets can no longer be sufficiently curved and will therefore remain crooked on the slightly inclined plane. Thanks to the inclined plane variable orientation consisting of leaf springs These drawbacks are eliminated.

In addition, due to the elasticity of the leaf springs 35, the proper slope or angle β is automatically adjusted by the flat material to be introduced even, and this in depending on its rigidity.

Referring to Figures 2 and 3, the introducer is also provided with an additional retaining member 42. The latter consists of a retaining wedge 43 intended to cooperate with one of the corners of the front edge leaves. This retaining corner 43 is integral of a lever 44 pivotally articulated on the wall lateral 10 by means of a pivot 45. A notching member 46 retains lever 44 in two determined positions by three stops 47, 48 and 49. In the position illustrated in solid lines in Figure 3, the retaining wedge 43 is in the active position and serves as a retaining member additional for thin and not very rigid sheets. In the position shown in broken lines on the Figure 3, the retaining wedge 43 is retracted. This position is used for rigid or thick materials, such as envelopes. The device could of course also function to satisfaction without the organ additional restraint 42, but the latter constitutes a additional safety element making the device particularly reliable even with very thin sheets.

Advantageously, the upper surfaces of the inclined plane fixed 31, extension 30 and possibly leaf springs 35 may be covered with a layer of substance modifying the coefficient of friction, such than a thin layer of tetrafluoroethylene. This layer is then used more particularly to erase fine inequalities and roughness of manufacturing the device.

FIG. 5 represents a variant of the device in which of the leaf springs 35 are replaced by levers 50 pivotally mounted by a pin 51 on the wall 9 of the magazine 6. Springs 52 urge the levers 50 in a rest position, as illustrated in the figure 5, in which the upper bearing surface 53 of the lever makes an angle close to 90 ° with a plane parallel to the background 8. This position corresponds to an introduction of very stiff leaves. On the contrary, when envelopes rigid are introduced, the lever 50 is tilted counterclockwise at the Figure 5 so as to be practically retracted inside from the opening 34 in the extension 30. The envelopes then also cooperate with the fixed inclined plane 31.

According to another variant illustrated in FIG. 6, the retaining member may be formed by a single piece 60, lever or plate, of substantially equal width to the width of the introducer and mounted pivoting on the anterior wall 9. The movement of pivoting or tilting of this part is delimited in both directions by stops 61,62 so that the upper bearing surface with variable orientation of this piece 60 has an angle β with a plane parallel to the bottom 8 varying between substantially 90 ° and 60 °. An element elastic, such as a spring 64, biases the workpiece toward a rest position against the stop 61 in which the angle β is substantially 90 °. Extension 30 of the anterior wall 9 is eliminated in this variant.

It is understood that the embodiments described above are in no way limiting and that they can receive any desirable changes to inside the frame as defined by claim 1. In particular, the position of the magazine 6 could be different, its bottom 8 could be inclined or horizontal. The support plate 12 can be fixed, the rollers training would then be requested during an operation of elastic introduction against sheets with extract. The number of leaf springs 35 may be different three, for example four or more. Instead of drive rollers, we can also plan other organs, such as a striking cylinder or training legs. Instead of the slope of the lever 50 (fig. 5) or 60 (fig. 6) is automatically adjusted using at springs 52 or 64, these springs can be replaced by a manual or other adjustment device allowing to adjust the part of the upper bearing surface of this lever depending on the sheets or envelopes to introduce. The device may also include a additional retaining member 42 comprising two corners of retractable retainer 43.

Claims (7)

1. A device for introducing flat items (14) to be printed, such as paper sheets and/or envelopes, for printers or typewriters, including a supply tray (6) with a bottom (8) which is substantially flat, in which a pile (14) of said flat items is placed and from which the items are extracted one by one and introduced into the printer (2), driving rollers (17) arranged on a driving shaft (20) so as to move the upper flat item of the pile to supply the same to the printer (2) or the typewriter, the device further including retaining members (31,35,43,50,60) designed for retaining the flat items arranged in said pile beneath the upper flat item including at least one movable part (35,50,60) mounted on the supply tray (6) and having an upper surface (37) designed for coming in contact with the front edge of said flat items to provide a bearing surface (37) with a variable orientation for said flat items positioned downstream of the driving rollers (17), the orientation of this variable bearing surface (37) with respect to said substantially flat bottom (8) being variable as a function of the rigidity of said flat items to be printed, characterized by the fact that the retaining members include, associated with said movable part, a fixed sloping plane (31) forming a first predetermined angle (α) with a plane parallel to said bottom (8) and extending from a front wall (9) substantially perpendicular to said bottom (8) of the supply tray, the movable part (35,50) being mounted on this front wall (9) and biased resiliently towards a neutral position, in which the variable bearing surface (37) forms a second angle (β) with said parallel plane greater than said predetermined angle (α) of the fixed sloping plane, the movable part (35,50) being oriented by the flat item so that said second angle (β) of the bearing surface (37) decreases as a function of the increase of the rigidity of the flat item to be introduced and takes values included between the one of said neutral position and the one of said predetermined angle (α).
2. A device according to claim 1, chacterized by the fact that said predetermined angle (α) is comprised between 30° and 85°, preferably between 60° and 65°, and by the fact that said seconde angle (β) is in the neutral position substantially equal to 90° and varies in the operative and introductive position between 90° and 30°, preferably between 90° and 60°.
3. A device according to claim 1 or 2, characterized in that it includes at least two movable parts constituted by leaf springs (35) fastened by one of their ends to the supply tray (6).
4. A device according to claim 1 or 2, characterized in that it includes at least two movable parts constitued by levers (50) mounted pivotally on the supply tray (6) and comprising a bearing surface for said flat items.
5. A device according to claim 3 or 4, characterized in that the movable parts (35,50) are at least partly engaged into openings (34) of the fixed sloping plane (31).
6. A device according to claim 1, characterized in that the retaining member consists of a single movable part (60) mounted pivotally on the supply tray (6) and includes two stops (61,62) limiting the pivoting motion of the movable part (60) and a resilient member (64) biasing the movable part (60) towards a neutral position determined by one of the stops (61), position in which the angle between the variable bearing surface of this movable part and a plane parallel to said bottom (8) is maximum.
7. A device according to one of the preceding claims, characterized in that the upper surface of the fixed sloping plane (31) and/or of said movable part (35,50,60) is covered with a layer of substance modifying the friction coefficient.

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