Abstract:
By providing an apparatus having a plurality of sheet feeders, each having a tray elongate in top plan view for supporting a stack of elongate sheets, wherein a tray can be displaced in an outward direction transverse to the longitudinal direction of the sheet feeders, it is made possible for a tray displaced in an outward direction to be tilted over a relatively large angle at a given vertical clearance from the other sheet feeders.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to an apparatus for individually feeding sheets from a plurality of stacks. 
         [0002]    Such an apparatus is known from Japanese patent application 59-167423. In this apparatus, two trays, each for holding a stack of sheets, are positioned above one another. In a feeding position, the trays are located to the side of a main housing of the apparatus. From the feeding position, the trays are each pivotable about a vertical axis near a corner of the tray at the front of the housing and at the housing side of the tray to a loading position projecting to the front of the apparatus. By pivoting the trays from the side to the front of the housing, loading of the trays is facilitated. 
         [0003]    However, loading the trays is still a relatively cumbersome task. For instance a common size for a package of sheets to be loaded is 500 sheets. Such a stack constitutes a rather heavy yet flexible structure with loose sheets on the outside which tends to flex away from the other sheets and of which the sheets easily shift relative to each other so the stack does not fit into the tray anymore. Such a stack is difficult to handle and many users prefer to split such a stack in two or more parts, which are loaded successively onto the tray each next part being loaded on top of a previous part. However, this is time consuming and if the stack consists of printed sheets and comprises mutually different sheets, as is usual in the processing of sheets into mail pieces or if the sheets are to be scanned for storage as electronic documents or copying, splitting up the stack during loading entails the risk of disturbing the order of the sheets or turning the sheets upside down. Moreover, especially for loading apparatuses for processing larger volumes of sheets, it would be advantageous if loading stacks of sheets into the trays could be carried out more quickly, since idle time during loading has a relatively large effect on overall productivity of such apparatuses. 
       SUMMARY OF THE INVENTION 
       [0004]    It is an object of the present invention to provide an apparatus for individually feeding sheets from a plurality of stacks each stack being supported by a tray in which the loading of stacks of sheets onto the trays is facilitated. 
         [0005]    According to the invention, this object is achieved by providing an apparatus according to claim  1 . Displacing a tray in an outward direction relative to the other trays and tilting the tray allows the top of the tray to be more easily accessible for a user to load a stack of sheets onto the tray. Because the tray is tiltable about an axis extending in its longitudinal direction, the tray can be tilted over a relatively large angle at a given maximum vertical clearance from other sheet feeders or sheets loaded therein. Vertical movability of the trays is limited because of the presence of other ones of trays above and/or underneath, which other trays may be fully loaded with a stack of sheets. Thus, accessibility of the tray for loading sheets is effectively improved within the limitations of vertical movability imposed by the presence of other trays above and/or underneath the tray. 
         [0006]    Particular elaborations and embodiments of the invention are set forth in the dependent claims. 
         [0007]    Further features, effects and details of the invention appear from the detailed description and the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a first example of an apparatus according to the invention; 
           [0009]      FIG. 2  is a top plan view of the apparatus shown in  FIG. 1 ; 
           [0010]      FIG. 3  is a perspective view of the apparatus shown in  FIGS. 1 and 2  with one tray in a loading position; 
           [0011]      FIG. 4  is a top plan view of a second example of an apparatus according to the invention; 
           [0012]      FIG. 5  is a perspective view of the apparatus shown in  FIG. 4  with one tray in the loading position. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    In the drawings, an apparatus  1  is schematically shown that can be mounted on or part of a system for processing sheets, such as a mail preparation system, a copying system or a printing system. In this example the feeding station  1  has four sheet feeders  2 , each for individually feeding sheets from a stack in the feeder. The sheet feeders  2  each have a tray  3 - 6  for supporting a stack of sheets  7  and are each provided with separating and transport rollers  8  for feeding the sheets  7  one by one in a feeding direction  9 . 
         [0014]    The trays  3 - 6  are each elongate for receiving a stack of elongate sheets, such as A4, letter or folio sized sheets, and arranged vertically above each other. In operation, sheets are separated and fed in a longitudinal feeding direction  9  of the tray from the stack  7  supported by the tray  3 - 6 . 
         [0015]    Each of the trays  3 - 6  of the sheet feeders  2  can be displaced relative to the other trays in an outward direction  10  transverse to the longitudinal feeding direction  9  from a feeding position in vertical alignment with the other trays  3 - 6  of the sheet feeders  2  and with a feeding path of the apparatus to a loading position out of the vertical alignment displaced to a position projecting forwardly of the other trays  3 - 6 . 
         [0016]    In  FIGS. 2 and 3 , the second tray from above  4  is in the loading position and the top of the tray  4  is clear from under the upper tray  3 . As shown in  FIG. 3 , the tray  4  in the loading position is tilted relative to its feeding position about an axis  11  extending in its longitudinal direction, such that an edge  12  of the tray  4  facing in the outward direction  10  is lowered relative to an opposite edge  13  of the tray  4 . 
         [0017]    Since the tray  4  in the loading position projects relative to the other trays and is displaced towards the user, it is better accessible for loading a stack of sheets. In this respect, it is particularly advantageous that the tray is better accessible from above, which is the general direction from which a stack of sheets is to be positioned in the tray. Furthermore, since the edge of the tray facing the person loading a stack into the tray is lowered relative to the opposite edge of the tray, the top side of the tray is tilted towards the user and to an orientation accommodated to the orientation in which a stack of sheets can be held comfortably, which further facilitates loading of a stack onto the tray. 
         [0018]    In this example the trays are suspended to be displaced outwardly first and to be subsequently tilted. The suspensions include straight guide rails known in the art to which the tray is suspended pivotably about an axis extending in its longitudinal direction. Furthermore guides are provided allowing pivoting movement relative to the orientation of the tray in the feeding position only if the tray is displaced outwardly to the loading position over some distance, so that scraping of the tray or of a stack of sheets loaded thereon along another tray or stack of sheets when the tray is displaced between the loading position and the feeding position is avoided. However, the combined translational and tilting movement between the loading position and the feeding position may also be achieved by providing a suspension having curved guide rails. The combined outward and downward displacement of the trays allows a compact arrangement of the trays in vertical alignment, yet provides an easily accessible loading position for each tray when it is displaced in the loading position. Since the trays are tiltable about axes extending in the longitudinal direction of the trays, the trays are tiltable over a relatively large angle within the confines of the limited amount of vertical space available. 
         [0019]    In  FIGS. 4 and 5  a second example of an apparatus  21  according to the invention is shown in which separating and transport members of the feeders  22  are each coupled to the tray  23 - 26  for lifting the separating and transport members relative to the tray  23 - 26  from a feeding position into a loading position when the respective tray  23 - 26  is displaced from the feeding position to the loading position. Thus, it is avoided that a supply roller  28  of the separating and transport members drags over the tray  23 - 26  or a topmost sheet of a stack  27  therein when the respective tray  23 - 26  is displaced between the feeding position and the loading position and there is no need for the operator to manually push the separating and transport members up before displacing a tray to the loading position. In the present example, this feature is realized in the form of a cam arm  34  on each of the trays  23 - 26 , which cam arm engages a guide  35  interconnecting pivot arms  36  via which rollers  28  of the transport members are pivotably suspended. If the tray is displaced out of the operating position towards the loading position, the cam  34  of that tray contact the guide  35  and thereby urges the guide  35  with the pivot arms  36  and the rollers  28  upwardly away from the stack  27  or from the bottom of the respective tray  23 - 26 . 
         [0020]    The side guides  33  of the feeders  22  on the side opposite the side to which the respective tray  23 - 26  is displaceable from the feeding position to the loading position is mounted such that, when the tray  23 - 26  of that sheet feeder  2  is displaced from the feeding position to the loading position, the side guide  33  remains stationary. This provides more room in the tray  23 - 26  for loading sheets and, when the tray  23 - 26  is returned to the feeding position, the loaded stack of sheets is automatically aligned by being pushed against the stationary side guide  33  by the side guide  32  that is displaceable with the tray  23 - 26 . However, according to the example shown in  FIGS. 1-3 , both side guides  12 ,  13  are in fixed positions relative to the tray, so that the side guides  12 ,  13  move with the trays between the loading position and the feeding position. 
         [0021]    One or more of the trays in the loading position may also be tiltable such that the end of the tray facing in the feeding direction is lowered relative to the end of the tray facing in a direction opposite the feeding direction or such that the end of the tray facing in a direction opposite the feeding direction is lowered relative to the end of the tray facing in the feeding direction. Depending on which end of the tray is lowered with respect to the feeding direction, an abutment may be provided on the end that is lowered. A stack of sheets loaded in a tray in the loading position as described above, can then easily be caused to slide in or opposite to the feeding direction against the abutment and be aligned in feeding direction. When the abutment is located at the end of the tray facing the feeding direction, the stack of sheets is always aligned at the front side of the tray and the position of the abutment does not need to be adjusted to the size of the sheets in feeding direction. The pivoting movement causing the end of the tray at the side in feeding direction to lift or to descend, may be a separate tilting movement about a second axis transverse to the tilting axis  11  in longitudinal direction or the tray may be suspended so as to be tiltable about an axis that is oriented obliquely to the feeding direction. 
         [0022]    While the invention has been illustrated and described in detail in the drawing and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.