Abstract:
A suction belt for conveying an object, includes a first area configured to allow applying a suction force to at least a part of an object; and a second area which is arranged adjacent to the first area, wherein a thickness of the suction belt changes at a transition from the first area to the second area.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of copending International Application No. PCT/EP2011/057318, filed May 6, 2011, which is incorporated herein by reference in its entirety, and additionally claims priority from European Applications No. 10162320.5, filed May 7, 2010, and US Application No. 61/332,338, filed May 7, 2010, all of which are incorporated herein by reference in their entirety. 
     
    
       [0002]    Embodiments of the invention relate to a suction belt, more specifically to a suction belt for conveying an object. 
       BACKGROUND OF THE INVENTION 
       [0003]    Suction belts are known in the art and may be used in a paper handling apparatus, e.g. an inserter, a assembly station, a merger, for conveying goods, e.g. one or more sheets of paper, one or more envelopes, one or more inserts.  FIG. 1  shows a portion of a conventional suction belt which may be formed from a plastic or rubber material and comprises a lower surface or bottom side  102  and an upper surface or top side  104  opposite to the bottom side  102 . Further, the belt  100  comprises opposing side faces  106  connecting the bottom side  102  and the top side  104  and one or more (a plurality of) holes or vias  108 . Each hole  108  extends through the body of the suction belt  100  from the bottom side  102  to the top side  104 . The suction belt  100  may be used in a suction conveyer which comprises a vacuum chamber and a vacuum source operatively connected to the vacuum chamber. The suction belt  100 , at least partially, extends over the vacuum chamber so that a suction force can be applied through the holes  108 . When an object is to be transported by the conveyor it is placed on the top side  104  of the suction belt  100  and the vacuum source is activated, thereby applying a suction force through the holes  108  to the object. Thus, the object is held on the top side  104  of the suction belt  100  and is transported as the belt is moved. 
         [0004]    In a paper handling apparatus there are situations when an additional object is to be added to an object already transported by the suction belt. In such a situation it is useful to ensure that upon adding the additional object no collision occurs. Further, there are continuously operating inserters in which an envelope and the goods move during the inserting process. The envelope is moved with a velocity lower than the velocity of the goods to be inserted so that as the envelope and the goods travel in the same direction, eventually, the goods reach the envelope and are inserted. In such a case, it is to be ensured that the goods securely cross the flap of the envelope. When a conventional suction belt is used, additional elements are to be provided for avoiding the above mentioned collisions. 
       SUMMARY 
       [0005]    According to an embodiment, a suction belt for conveying an envelope having an envelope front side, an envelope back side and an envelope flap at the envelope front side may have: a first area configured to allow applying a suction force to at least a part of the envelope; and a second area which is arranged adjacent to the first area, wherein a thickness of the suction belt changes at a transition from the first area to the second area, and wherein the envelope is arranged on the suction belt such that its envelope flap is arranged on the first area adjacent to the second area, so that during a filling process one or more goods to be inserted into the envelope pass the second area without colliding with the envelope flap. 
         [0006]    According to another embodiment, a suction conveyor may have: vacuum generator, a first, driven roller, a second roller, and a suction belt extending around the first roller and around the second roller, the suction belt for conveying an envelope having an envelope front side, an envelope back side and an envelope flap at the envelope front side, and including: a first area configured to allow applying a suction force to at least a part of the envelope; and a second area which is arranged adjacent to the first area, wherein a thickness of the suction belt changes at a transition from the first area to the second area, and wherein the envelope is arranged on the suction belt such that its envelope flap is arranged on the first area adjacent to the second area, so that during a filling process one or more goods to be inserted into the envelope pass the second area without colliding with the envelope flap, and wherein the vacuum generator is arranged to provide a suction force to be applied to the envelope arranged on the first area of the suction belt. 
         [0007]    Embodiments of the invention provide a suction belt for conveying an object, comprising a first area configured to allow applying a suction force to at least a part of an object, and a second area which is arranged adjacent to the first area, wherein a thickness of the suction belt changes at a transition from the first area to the second area. 
         [0008]    Further embodiments are defined in the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Embodiments of the present invention will be detailed subsequently referring to the appended drawings, in which: 
           [0010]      FIG. 1  shows a portion of a conventional suction belt, 
           [0011]      FIG. 2  shows an isometric view of a portion of a suction belt in accordance with embodiments of the invention, 
           [0012]      FIG. 3  shows a further embodiment of the suction belt having a different configuration of the second areas, 
           [0013]      FIG. 4  shows yet another embodiment of the suction belt in accordance with which the second area is arranged at a distance from the edges of the belt, 
           [0014]      FIG. 5  shows a suction belt in accordance with another embodiment, wherein  FIG. 5(   a ) is a sectional view of taken along a line a-a′ shown in  FIG. 5(   b ) which is a top view of the belt, 
           [0015]      FIG. 6  shows a suction belt in accordance with yet another embodiment, wherein  FIG. 6(   a ) is a sectional view taken along a line a-a′ shown in  FIG. 6(   b ) which is a top view of the belt, 
           [0016]      FIG. 7  shows in  FIGS. 7(   a ),  7 ( b ) and  7 ( c ) different shapes of the second area of the suction belt, 
           [0017]      FIG. 8  shows another embodiment of the suction belt, wherein  FIG. 8(   a ) is a sectional view taken along lines a-a′ in  FIG. 8(   b ) which is a top view of the belt, 
           [0018]      FIG. 9  shows another embodiment of the suction belt; 
           [0019]      FIG. 10  shows yet another embodiment of the suction belt; 
           [0020]      FIG. 11  shows a suction conveyer using the suction belt in accordance with embodiments of the invention; 
           [0021]      FIG. 12  shows a schematic view of a section of an inserter comprising the suction conveyor of  FIG. 11 ; and 
           [0022]      FIG. 13  shows a suction belt in accordance with further embodiments of the invention, wherein  FIG. 13(   a ) is an isometric view of a part of the belt, and  FIG. 13(   b ) is a sectional view along the line b-b′ in  FIG. 13(   a ). 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]      FIG. 2  shows an isometric view of a portion of a suction belt  200  in accordance with embodiments of the invention. The suction belt  200  may be formed from a plastic or a rubber material and comprises a lower surface or bottom side  202  and an upper surface or top side  204 . The bottom side  202  and the top side  204  are connected by opposing side faces  206 . The suction belt  200  comprises at least two holes or vias  208  extending through the suction belt body between the bottom side  202  and the top side  204 . A thickness d of the suction belt  200  is defined by the length or dimension between the bottom side  202  and the top side  204 . The suction belt  200  comprises a plurality of first areas  210  and a plurality of second areas  212 . The thickness d 1  of the first areas  210  differs from the thickness d 2  of the second areas  212 . More specifically, at a first transition  214  between the second area  212  and the first area  210  the thickness d of the suction belt  200  changes from d 2  to d 1 . Thus, there is a distance d 3  between the top surface  204   1  in the first area  210  and the top surface  204   2  in the second area  212 . The height d 3  is equal to or higher than a thickness of an object held on the first area so that, e.g. an object travelling across the second area is lifted far enough above the object held on the belt to avoid a collision. In case of an inserter the height d 3  is selected to be equal to or higher than a thickness of an envelope flap so that goods to be inserted can securely pass the flap but still hits an envelope mouth of the opened envelope. In an assembly station the height (d 3 ) may be selected dependent from the maximum number of objects that can be assembled into a stack. 
         [0024]    Thus, by means of a suction belt  200  as shown in  FIG. 2 , in accordance with embodiments of the invention, an apparatus for transporting an envelope in an inserter is provided, wherein the suction belt  200  comprises the first area or suction section  210  for holding an open flap of an envelope and at least a part of an envelope body, and wherein the second area  212  forms means for providing an elevation such that an open flap of the envelope can be arranged behind the elevation. 
         [0025]    In the embodiment of  FIG. 2 , the second area  212  is a contoured section of the belt which is shaped as a ramp. At a second transition  216  between the first area  210  and the second area  212  the top side  204  of the belt  200  starts to rise or ascend linearly until the height d 3  is reached so that a first, upwardly rising part of the second area  212  is formed, followed by a second, horizontal part that extends to the first transition  216  where a third, vertical part is formed. 
         [0026]    When using the suction belt for transporting one or more sheets of paper, e.g. a single sheet or a stack of sheets, one or more additional sheets can be placed on the stack without any collision because it is moved out of the plane  204   1  in which the sheet is held by the suction force, thereby allowing to cross the already held sheet. Also when inserting goods into an envelope held on the belt with its flap at the first transition  214 , the goods can be moved securely into the envelope over the flap. In accordance with embodiments the second area  212  is an integral part of the suction belt  200 , i.e. the first and second areas  210 ,  212  are formed from the same belt  200 . Therefore, a fixed positional relationship between the two areas is ensured allowing for a secure and reliable operation. 
         [0027]    In the embodiment of  FIG. 2 , the first area  210  comprises a plurality of holes  208  arranged at predefined intervals between two consecutive second areas  212 . However, in accordance with other embodiments of the invention it is not necessary that the entire first area  210  between two second areas  212  is provided with holes, rather a first part  210   1  having the holes and a second part  210   2  having no holes may be provided. Also, it is noted that the second areas  212  in accordance with embodiments do not comprise any holes. 
         [0028]      FIG. 2  shows a suction belt  200  having the second area  212  extending over the entire width w of the belt  200 , however, the invention is not limited to such embodiments.  FIG. 3  shows a further embodiment of the suction belt  200  having a different configuration of the second areas  212 . The second area  212  is formed of two separate parts  212   1  and  212   2  each extending over only a part of the width w of the belt  200 . More specifically, the first part  212   1  is arranged at a first edge  218  of the belt  200  and extends in the width direction w by a distance w 1  towards a second, opposing edge  220 . The second part  212   2  extends from the second edge  220  in the width direction towards the first edge  218  by a distance w 2 . Thus, the parts  212   1  and  212   2  are arranged with a gap g there between. 
         [0029]      FIG. 4  shows yet another embodiment of the suction belt  200  in accordance with which the second area is arranged at a distance from the edges  218  and  220  of the belt  200 . The second area  212  has a width w 1  and may be arranged at the center of the belt  200 . However, also an eccentric arrangement may be desired. The second area  212  is arranged at a distance g 1  from the first edge  218  and at a distance g 2  from the second edge  220 , wherein the distances g 1  and g 2  may be the same or may be different. 
         [0030]      FIG. 5(   a ) shows a sectional view of a suction belt in accordance with another embodiment taken along a line a-a′ shown in  FIG. 5(   b ) which is a top view of the belt. Other than in the embodiment described with regard to  FIG. 2 , the entire first area  210  comprises the holes  208 , i.e. there is no area  210   2 . 
         [0031]      FIG. 6(   a ) shows a sectional view of a suction belt in accordance with yet another embodiment taken along a line a-a′ shown in  FIG. 6(   b ) which is a top view of the belt. Other than in the embodiments described thus far, instead of providing a number of holes arranged along the longitudinal extension of the suction belt  200 , a longitudinal slot or slit  222  is formed that extends from the bottom side  202  to the top side  204 . 
         [0032]    In the embodiments described with regards to  FIGS. 2 to 6  the second area  212  has a first linearly upward extending part  212   a  (see  FIG. 5(   a )), a second, horizontal part  212   b,  and a third, vertical part  212   c.  Instead of such a ramp-shaped part or elevation, also other shapes may be used. 
         [0033]      FIG. 7(   a ) shows the second area  212  comprising a first part  212   a  that starts to rise or ascend from the second transition  216  upwards in a curved or bend shape until it reaches the second, horizontal part  212   b.  At the first transition  214  a third, vertical part  212   c  follows.  FIG. 7(   b ) shows a further embodiment having a first part  212   a  linearly extending upward from the second transition  216  to the first transition  214 , where the vertical part  212   c  follows. This ramp does not have a horizontal part  212   b.  Instead of the linear part  212   a,  also a curved part may be used.  FIG. 7(   c ) shows yet another embodiment of the second area  212  having a curved surface  212   d.    
         [0034]    Another embodiment of the suction belt will now described with reference to  FIG. 8  in which the second areas  212  comprise a first, vertical part  212   a  extending upwardly at the second transition  216 , a horizontal part  212   b  followed by a second vertical part  212   c  at the first transition  214 . Further, from the embodiment of  FIG. 8  it is clear that the suction belt is not limited to openings having the shape of holes  208  or slits  222 , rather, a plurality of slits  222  may be provided.  FIG. 8(   b ) is a top view of the belt  200  and the sectional view of  FIG. 8(   a ) is taken along lines a-a′. 
         [0035]    Further it is noted that any combination of holes and slits may be used for realizing the openings for applying a suction force. Also holes or silts arranged side by side in the width direction may be provided. 
         [0036]      FIG. 9  shows another embodiment of the suction belt in accordance with which the first area  210  has a top side that rises starting from the first transition  214  to the second transition  216  up to the height of the second area  212 . Alternatively, as is shown in  FIG. 10 , the top side of the second area  210  may rise to a first height below the height of the second area. After a horizontal part the top side starts to rise again. 
         [0037]      FIG. 11  shows a suction conveyer  300  comprising a vacuum means having a vacuum chamber  302  and a vacuum pump  304 . Further, a first roller  306  and a second roller  308  driven by a motor  310  are provided. A suction belt  200  in accordance with embodiments of the invention extends around the two rollers  306  and  308 , and the vacuum chamber  302  applies a suction force to the openings  208  of the suction belt  200  for holding an object transported by the belt  200 . 
         [0038]      FIG. 12  shows a schematic view of a section of an inserter  400  comprising the suction conveyor  300  of  FIG. 11  for transporting an envelope or cover along an inserting or filling path. The suction conveyor  300  comprises a suction belt  200  in accordance with embodiments of the invention. The inserter  400  further comprises a goods transport  402  comprising a belt or a chain  404  extending around respective rollers (not shown). One or more pushers  406  are mounted to the belt  404 . The pushers  406  are provided for engaging with a trailing edge  408  of an object  410  to be inserted into an envelope  412  moved by the suction conveyor  300 . The suction conveyor  300  moves the envelope  412  with a velocity that is slower than the velocity of the goods transport  402  so that along the inserting or filling path the object  410  will eventually be inserted into the envelope  412 . The inserter  400  further comprises air nozzles  414   a,    414   b  which blow air towards the envelope  412  for opening it. Further, a separating device  416  is provided which comprises a belt or chain  418  arranged above the suction conveyor  300  and extending around two roller (of which only one roller  420  is shown in  FIG. 12 ). One or more separating elements  422  are mounted to the belt  418  and are provided to engage with a trailing edge  412   a  of a first side  412   b  of the envelope  412  and to maintain the first side  412   b  separated from a second side  412   c  of the envelope  412 . By means of the belt  418  the separating element  414  is moved together with the envelope  412  so that the separation is maintained over at least a part of the filling path (e.g. at least until a leading edge of the object  410  is arranged inside the envelope  412 ). 
         [0039]    The envelope  412  is arranged on the suction belt  200  in its first area  210  with its second side  412   c  in contact with the suction belt  200 , more specifically, a part of the second side  412   c  of the envelope  412  is arranged on the second part  210   2  having no holes. Another part of the second side  412   c  to which an envelope flap  412   d  is arranged on the first part  210   1  of the belt  200  having the holes. As can be seen, the envelope  412  is placed on the suction belt  200  such that a trailing edge of the flap  412   d  is arranged at the transition  214 . The thickness of the suction belt  200  in the second area  212  is such that the distance d 3  (see FIG.  2 —the height of the upper side  204   2  of the second area  210  above the upper side  204   1  of the first area  210 ) equals at least the thickness of the flap  412   d.  In accordance with embodiments the distance d 3  is less than a maximum opening of an envelope throat  412   e  during the filling process. In any case the height d 3  is selected such that the object  410  is raised from the transport level of the envelope  412  so that it securely passes the flap  412   d  on its way into the envelope. 
         [0040]    In the embodiments described so far the suction belt included the holes, the diameter of which defined respective suction areas, i.e., an area in which a suction force can be applied through the hole to an object on the belt. However, the invention is not limited to this kind of suction areas.  FIG. 13  shows a suction belt in accordance with further embodiments of the invention, wherein  FIG. 13(   a ) is an isometric view of a part of the belt, and  FIG. 13(   b ) is a sectional view along the line b-b′ in  FIG. 13(   a ). The suction belt  200  comprises the holes  208  extending from the bottom side  202  of the suction belt  200  to its top side  204 . The top side  204  comprises shallow portions  230   1  to  230   5 , e.g. shallow recesses or shallow cups. In accordance with embodiments small shallow recesses are provided having a width along the width direction of the belt  200  and a length along the longitudinal direction of the belt  200 , wherein the width is greater than the length, see e.g. recesses  230   1 ,  230   3 ,  230   4 , and  230   5 . In accordance with other embodiments large recesses are provided having a length greater than a width, see e.g. recesses  230   2 . In accordance with embodiments the belt  200  comprises only small recesses, only large recesses or both small and large recesses. The holes  208  extend from the bottom side to the recesses. As can be seen from  FIG. 13 , in accordance with embodiments, a shallow recess may have a diameter that is larger than a diameter of a hole  208  connected thereto. One or more holes may be provided at the center of the recess or at another part of the recess. In accordance with these embodiments the suction area is greater than the diameter of the hole. The suction area is defined by the recess formed in the top side of the belt. It is noted that  FIG. 13  shows that each recess is provided with one hole. However, other embodiments may comprise at least one recess including two or more holes. 
         [0041]    In accordance with the embodiment depicted in  FIG. 13 , when using the belt to transport envelopes, a combination of one large recess and a plurality of small recesses is used, wherein the large recess  230   2  is provided for applying a suction force greater than normal to the envelope flap, and which is greater than a suction force provided by a small recess. By arranging the large recess at a predetermined position along the belt, it is possible to apply the higher suction force to a desired area of an object on the belt. For example, in case of transporting an envelope, the large recess  230   2  is provided close to the first transition  214 , advantageously with one small recess  230   1  between the large recess  230   2  and the transition  214 . It is noted that dependent on the circumstances also more than one small recess may be provided between the large recess  230   2  and the transition  214 . In accordance with other embodiments no small recesses may be provided between the large recess  230   2  and the transition  214 , i.e., the large recess is arranged at a distance from the transition  214  that may be set dependent from the dimension of the envelopes to be handled. 
         [0042]    While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and compositions of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations and equivalents as fall within the true spirit and scope of the present invention.