JP4076526B2 - Sheet discharge device for printing machine - Google Patents

Description

  The present invention relates to a sheet discharge apparatus for a printing machine, for example, an electrophotographic type printing machine, and the sheet discharge apparatus includes at least one sheet conveyance mechanism that is rotationally driven. It relates to a type in which a mechanism is provided for receiving or gripping the leading edge of the sheet and for discharging and stacking the sheet after traveling on a rotating track.

  A sheet discharge device with a rotationally driven sheet transport mechanism is known, for example, from US Pat. No. 4,252,309.

In the known sheet conveying mechanism, the leading edge is pushed into the slit of the substantially disk-shaped sheet conveying mechanism. The sheet thus gripped is entrained from the upper gripping position by turning the sheet transport mechanism half-turned, turned over, and then discharged at the reached deep position (level) of the discharge point. Stacked on the sheet. When the slit passes through the stopper and the sheet is pushed back by the stopper, the sheet to be discharged is automatically released from the slit.
US Pat. No. 4,252,309

  The object of the present invention is therefore to provide an improved sheet discharge device of the type described at the outset, preferably having an ideal discharge capacity suitable for sheets of different sizes and weights. is there.

  According to the apparatus of the present invention for solving this problem, at least two sheet transport mechanisms are provided, and the plurality of sheet transport mechanisms rotate about a common axis substantially independently of each other. One sheet transport mechanism is prepared to receive or grip a subsequent sheet while one sheet transport mechanism is transporting or discharging the preceding sheet. ing.

  The known sheet conveying mechanism described in the background art described above includes two slits positioned opposite to each other in the diametrical direction for accommodating the leading edge of the sheet, so that the sheet conveying mechanism is preceded in principle. While the sheet is being ejected, it is again ready to take on subsequent sheets.

  In practice, however, this is only true if the sheet to be received has an appropriate size. Advantageously, the sheet is delivered to the sheet conveying mechanism by a conveying roller provided at the end of the conveying path for the substrate. Good discharge of the sheet is obtained when the conveying roller delivers the trailing edge of the sheet immediately, especially when the leading edge of the sheet reaches the stopper in the delivery position. This is because the sheet is softly discharged into the sheet stack. In this sense, it is desirable that the sheet has a length that surrounds the sheet conveyance mechanism over approximately half, that is, a length corresponding to a half circumference of the outer surface of the sheet conveyance mechanism. However, the sheet does not always have such a length. Longer or shorter sheets are also conveyed. In any case, for example, a relatively heavy and relatively hard substrate cannot be bent greatly without breakage, so the radius of the sheet transport mechanism is measured in terms of the sheet size in view of such substrate. In this case, it is desirable to select a length larger than that length in advance. Further, in order to use the sheet discharging apparatus as a whole, it is desirable that the sheet is conveyed with as uniform a sheet flow as possible so that there is no excessively large gap between successive sheets. However, it is desirable that successive sheets do not overlap.

  Free slits that attempt to take on subsequent sheets can be prepared too early or too late depending on the situation. In view of the situation described, mounting a large number of slits (or other types of holding mouth-shaped accommodation portions) in the sheet turning mechanism does not solve the problem.

  However, the configuration of the present invention optimizes transport. This is because another sheet conveying mechanism or a plurality of sheet conveying mechanisms can be prepared independently in accordance with the size of the sheet in a precise time.

  According to a particularly advantageous embodiment of the invention, there is provided a sheet turning mechanism cooperating with the sheet transport mechanism, the sheet turning mechanism substantially being a mantle surface that serves as a mounting for the sheet. Forming a curved trajectory for the sheet to be conveyed, wherein each sheet conveying mechanism comprises at least one cover element for covering the received leading edge of the sheet, the leading edge of the sheet being conveyed It is gripped and entrained between one of the cover elements of the mechanism and the outer surface of the sheet turning mechanism.

  When using a storage slit for the leading edge of the sheet, the leading edge of the sheet is damaged by the slit, and in some cases, the sheet is pushed into the slit and held to the desired discharge location with sufficient satisfaction and accuracy. There is a risk that it will not be.

  A further object of the present invention is to provide a functional and selective one.

  In the sheet discharge apparatus of the present invention for solving this problem, the functions are advantageously distributed to different components, so that more reliable and desired functionality can be obtained.

  The sheet turning mechanism mainly takes over the disc main body function and provides a contact part and a mounting part for the sheet. In this case, the sheet turning mechanism does not necessarily need to be formed in a disk shape, but another implementation. In form, it can also be formed in the shape of a wheel or some kind of segment.

  The sheet transport mechanism takes on, among other things, a part of the holding function by providing a cover element, which covers the leading edge of the sheet between the cover element and the outer surface of the sheet turning mechanism adjacent to the cover element. Thus, the leading edge is securely held without being damaged. Thus, the sheet transport mechanism does not have to be formed in a disc shape at all, and according to an advantageous embodiment of the invention, it is substantially formed as a two-armed swivel beam, the swivel beam being radially outward The two free end regions are each provided with a cover element. With the cover elements at both ends, the sheet transport mechanism is already ready to take over the subsequent sheet, either at the time of discharging the preceding sheet, or at least immediately after discharging. Advantageously, in any configuration, a substantially rotationally symmetric seat turning mechanism is in principle ready at each rotational position.

  The cover element is advantageously flat as a tongue or strip, and in some cases is elastic and flexible, which also prevents damage to the leading edge of the seat.

  In this case, the cover element is formed as a tongue or strip extending substantially parallel along the curved trajectory of the seat turning element.

  According to another embodiment of the present invention, a plurality of sheet conveying mechanisms and sheet turning mechanisms are provided two by two and are arranged mirror-symmetrically with each other on a common axis, The sheet conveying mechanism is disposed between both sheet turning mechanisms, and the sheet leading edge is an extended portion extending in parallel to a common axis of the sheet conveying mechanism and the sheet turning mechanism, Two of at least four sheet conveying mechanisms and two sheet turning mechanisms are collectively held.

  In this way, the sheet is advantageously gripped reliably over its entire width, and in particular is avoided from tilting or twisting due to conveyance.

  In order to achieve particularly reliable gripping, the cover of the cover element in the sheet transport mechanism is advantageously covered by the sheet in a position where the sheet-facing surface adds the sheet thickness to the radius of the outer surface of the sheet turning mechanism. Located slightly away from the common axis than the outer surface covered by the element, with the seat leading edge at the stretch and slightly pressed towards the common axis so that stress is generated in the area of the cover element And bend.

  As already known from the prior art, the apparatus of the present invention is also provided with a stopper for the leading edge of the sheet, and the stopper and the sheet conveying mechanism cooperate in discharging the sheet.

  Particularly with respect to the shortest possible sheet size, the device according to the invention is advantageously provided with at least one guide element that blocks the gripped sheet in at least the centrifugal direction, the guide element having a curvature formed by the sheet. In order to forcibly maintain the radius, it is provided between the gripping position and the sheet delivery position.

  The sheet gripped and conveyed in this way is surely brought into contact with the outer surface of the first sheet conveying mechanism at the intermediate position even if it is intended to release the trailing edge from the conveying roller at an extremely early point. The

  In particular, by providing at least two sheet transport mechanisms according to the present invention, it is possible to create more time for discharging the sheet, and if desired, at least one displacement mechanism connected to at least one sheet transport mechanism is provided. The displacement mechanism is provided for laterally moving the sheet to be discharged substantially parallel to the common axis of the sheet conveying mechanism.

  Embodiments of the invention do not limit the scope of the invention and other configurations can be created from these embodiments.

  Next, embodiments of the present invention will be described in detail using the illustrated examples.

  1 to 4 show side views of the sheet conveyance mechanism according to the present invention at various rotational positions in order to easily understand the function progress of the sheet discharge apparatus (paper discharge apparatus) of the present invention.

  FIG. 1 is a side view of a substantially disk-shaped sheet turning mechanism 1. The sheet turning mechanism 1 is brought into contact with the sheet turning mechanism 1, and the sheet turning mechanism is moved by the last-stage transport roller 2 that forms the end of the transport path for the printed material. Delivered to 1.

  In order to force the sheet to come into contact with the sheet turning mechanism 1, the pressing roller 3 is used as a guide element that blocks the sheet in the centrifugal direction. The sheet can be displaced along the circumference, so that sheets of various sizes can be reliably guided for a sufficient time.

  In the embodiment shown in FIGS. 1 to 4, the sheet discharging apparatus of the present invention is further provided with two sheet conveying mechanisms 4 and 5, and these sheet conveying mechanisms 4 and 5 are substantially two-arm swivels. It is formed as a beam and is provided with a tongue or strip-like cover element (Uebergriffelement) 6 at each free end. A sheet to be conveyed can be inserted and held in the gap between the sheet turning mechanism 1 and the cover element 6 at the leading edge of the sheet, and the sheets corresponding to the sheet turning mechanism 1 and each cover element 6 can be held. When the conveyance mechanisms 4 and 5 rotate together, the conveyance mechanisms 4 and 5 can convey toward the stopper 7, where they can be discharged and stacked on the sheet stack (pile) 8. Since both the sheet conveying mechanisms 4 and 5 can rotate independently of each other around the common rotating shaft 9, these sheet conveying mechanisms 4 and 5 can occupy different rotational positions. As a result, the sheets can be sequentially received from the conveying roller 2 at intervals as short as possible and discharged to the sheet stack 8. The main position of the cover element 6 is shown in an easy-to-understand manner by providing reference numerals A, B, C and D in FIGS.

  The function progress of the paper discharge device of the present invention will be described below with reference to FIGS.

  The preceding first sheet transport mechanism 4 is positioned by the cover element A so as to occupy the sheet receiving position. The succeeding second sheet conveying mechanism 5 is the cover element D and follows the preceding first sheet conveying mechanism 4 at a slight interval.

  As a result, the cover element C is positioned as follows on the opposite side (region of the stopper 7) of the second sheet conveying mechanism 5, that is, positioned so that the sheet can be discharged at the stopper 7 just at that position. Yes.

  In this case, the second sheet conveying mechanism 5 stays at the aforementioned position until the first sheet conveying mechanism 4 rotates downward together with the subsequent sheet to be discharged and attempts to enter the region of the stopper 7. Can do.

  The cover element 6 to be discharged in the stopper 7 is temporarily stopped in the area of the stopper 7 in an advantageous manner, and is required, but the sheet to be discharged is removed from the sheet conveying mechanism. There is provided at least one displacement mechanism (not shown) coupled to at least one of the sheet conveying mechanisms 1, 4, 5 for lateral movement substantially parallel to the common shaft 9. This configuration is advantageous when the sheet is to be moved eccentrically (offset) before the stopper 7.

  When the cover element A rotates downward together with the subsequent sheet to be discharged and substantially occupies the position of the cover element C, the cover element D has already reached the sheet receiving position.

  Since both the sheet conveying mechanisms 4 and 5 run in tandem, they do not collide.

  Here, the sheet conveying mechanisms 4 and 5 alternately take over the guide function.

  Further, according to an important point in such an embodiment, after the sheet starts to be conveyed toward the stopper 7, the subsequent sheet conveying mechanism 4 or 5 is positioned below the sheet to be discharged. Along with the element 6, it can travel to the sheet storage position.

  Therefore, in order to guide the subsequent cover element 6 to the sheet storage position, it is not necessary to use a slight intermediate space between the two sheets reaching the conveying roller 2.

  In the embodiment of the present invention, the following steps are formed.

First step / fourth step (FIG. 1):
The sheet transport mechanism 4 occupies the sheet storage position with the cover element A.
The sheet conveying mechanism 5 follows the sheet conveying mechanism 4 at a slight interval with the cover element D;
In parallel, the sheet transport mechanism 5 can eject the sheet at the edge of the stack in the segment C, or move it eccentrically at that position.

Second step (FIG. 2):
The sheet transport mechanism 4 moves toward the stopper 7 together with the newly stored sheet.
-The sheet transport mechanism 5 remains in the position of the first step.
The pressing roller 3 assists in sheet conveyance;

Third step (FIG. 3):
The sheet transport mechanism 4 continues to move toward the stopper 7 together with the sheet via the cover element A.
The sheet conveying mechanism 5 rotates until the cover element D occupies the sheet storage position.

Fourth step / first step (FIG. 4):
The sheet transport mechanism 4 guides the sheet to the stopper 7 via the cover element A, and temporarily stops there. The sheet located at the stopper 7 can also be moved eccentrically.
The cover element D occupying the sheet storage position can store subsequent sheets;

  The steps shown in FIG. 3 and FIG. 4 that are performed one after the other may proceed with time overlap. This is advantageous when a relatively short size sheet is used. While the preceding sheet is still being conveyed towards the stopper 7, the next sheet can already be inserted into the subsequent cover element 6. When the trailing edge of the sheet is conveyed away from the operating range of the pressing roller 3, the subsequent cover element 6 can immediately enter the pressing roller range together with the next sheet.

  In short, the succeeding sheet follows the preceding sheet with a suitable intermediate space. In order to prevent a gap from being generated in the transport region of the cover element 6 after accommodating two extremely short sheets (when only two cover elements 6 are provided as a whole, the disc-shaped sheet turning mechanism 1 Both cover elements 6 are located in the half of the sheet), and both the sheet conveying mechanisms 4 and 5 are provided with two cover elements 6 instead of one. As a result, the cover element 6 does not need to be accelerated and transported to the sheet storage position over half the circumference of the turning portion, and the gap is always closed automatically.

  FIG. 5 is a perspective view showing an embodiment of the paper discharge device of the present invention. The same reference numerals are used for the same components as those shown in FIGS.

  In particular, as can be seen from FIG. 5, the two sheet turning mechanisms 1 and the four sheet conveying mechanisms 4 and 5 are mounted on the shaft 9 mirror-symmetrically, and both the sheet turning mechanisms 1 are located outside. In addition, the sheet conveying mechanisms 4 and 5 are located between both the sheet turning mechanisms 1.

It is a side view which shows the sheet | seat conveyance mechanism of this invention in 1 rotation position.

It is a side view which shows the sheet | seat conveyance mechanism of this invention in 1 rotation position.

It is a side view which shows the sheet | seat conveyance mechanism of this invention in 1 rotation position.

It is a side view which shows the sheet | seat conveyance mechanism of this invention in 1 rotation position.

FIG. 5 is a perspective view showing a paper discharge device of the present invention including the sheet conveying mechanism shown in FIGS. 1 to 4.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Sheet turning mechanism, 2 Conveying roller, 3 Press roller, 4,5 Sheet conveying mechanism, 6 Cover element, 7 Stopper, 8 Sheet stack, 9 axis, A, B, C, D Cover element

Claims (9)

An apparatus for discharging a sheet for a printing machine, for example, an electrophotographic printing machine, wherein the sheet discharging apparatus comprises at least one rotationally driven sheet conveying mechanism, and the sheet In a type in which the transport mechanism is provided for receiving or gripping the leading edge of the sheet and discharging and stacking the sheet after traveling on the rotating path,
At least two sheet conveying mechanisms (4, 5) are provided, and the plurality of sheet conveying mechanisms (4, 5) can be rotated about a common axis (9) substantially independently of each other. The other sheet conveying mechanism (4, 5) receives the succeeding sheet while the one sheet conveying mechanism (4, 5) is formed and conveys or discharges the preceding sheet. Or a sheet turning mechanism (1) prepared for gripping and cooperating with the sheet transport mechanism (4, 5) is provided, and a plurality of sheet transport mechanisms (4, 5) and a sheet turning mechanism are provided. Two mechanisms (1) are provided and are arranged mirror-symmetrically with each other on a common axis (9), and all the sheet conveying mechanisms (4, 5) are connected to both sheets. It is arranged between the turning mechanism (1) and the front edge of the seat The extending portion extending in parallel to the common axis (9) of the sheet conveying mechanism (4, 5) and the sheet turning mechanism (1), and is a total of at least four sheet conveying mechanisms (4, 5). A sheet discharge device characterized in that it is held together by two and two sheet turning mechanisms (1) . Sheet over preparative deflection mechanism (1) is, in the mantle surface which serves as a mounting portion for the sheet forms a curved trajectory for sheets to be substantially conveyance, the sheet transport mechanism (4, 5) comprises at least one cover element (6) for covering the sheet leading edge to be received, the sheet leading edge being one of the cover elements (6) of the sheet transport mechanism (4, 5) and the sheet 2. The device according to claim 1, wherein the device is gripped and entrained with the mantle surface of the deflection mechanism (1).   3. The device according to claim 2, wherein the sheet turning mechanism (1) is substantially disc-shaped or wheel-shaped.   Each sheet conveying mechanism (4, 5) is substantially formed as a two-armed swivel beam, and each of the sheet conveying mechanisms (4, 5) is 1 in each of the radially outward free end regions. Device according to claim 2 or 3, comprising two cover elements (6).   A cover element (6) according to any one of claims 2 to 4, wherein the cover element (6) is formed as a tongue or strip extending substantially parallel to the curved trajectory of the sheet turning mechanism (1). apparatus. The cover element (6) of the sheet at a position where the sheet-facing surface of the cover element (6) in the sheet transport mechanism (4, 5) is the radius of the outer surface of the sheet turning mechanism (1) plus the sheet thickness. ) Is located at a slight distance from the common axis (9) than the outer surface covered by the common axis (9) so that the leading edge of the seat is an extension and the stress is generated in the region of the cover element (6). 2. The device according to claim 1 , wherein the device is slightly pressed and deflected towards (9). A stopper (7) for the leading edge of the sheet is provided, and the stopper (7) and the sheet conveying mechanism (4, 5) cooperate to discharge the sheet. 7. The apparatus according to any one of items 6 to 6 . A pressing roller (3) is provided as at least one guide element for blocking the gripped sheet at least in the centrifugal direction, and the pressing roller (3) forcibly maintains the radius of curvature formed by the sheet. for, it provided between the gripping position and the delivery position of the seat apparatus of any one of claims 1 to 7. At least one displacement mechanism connected to at least one sheet conveyance mechanism (4, 5) or a sheet turning mechanism (1) is provided, and the displacement mechanism is a sheet conveyance mechanism ( device substantially provided in order to perform a lateral movement in a direction parallel to any one of claims 1 to 8 relative to the common axis (9) of the 4, 5).

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