Device for supplying thin objects to a conveying device in an overlapping manner

Abstract: Device for supplying piled, thin objects, in particular envelopes (1), to a conveying device (3) in an overlapping manner, characterised in that it contains a rotor (7) which can rotate around a stator (5) and means (9) for driving the rotor (7), whereby the stator (5) is equipped with a chamber (6) opening in its outer perimeter which is connected to a vacuum source (10), and whereby the rotor (7) is provided with openings (8) which are temporarily situated opposite to the exit of the chamber (6) during the rotation of the rotor (7).

Description: The present invention concerns a device for supplying thin, piled objects, in particular envelopes, to a conveying device in an overlapping manner. Such devices are used for supplying envelopes to be printed to a printing machine. As the envelopes are presented to the printing machine by the conveying device in an overlapping manner, when they are taken up one by one by the printing machine, they have to cover a shorter distance than if they would have lain entirely one after the other on the conveying device, which allows for a higher print speed. It is clear that it is important hereby that the successive envelopes overlap one another at the same, invariable distance or that they are situated at equal distances from one another with their front side or back side. Known devices of the above-mentioned type contain friction belts, whereby the envelopes are taken one by one from the bottom side of a pile by means of friction. Such devices do not allow to obtain the required invariable overlap of the envelopes, however. Other known devices contain a perforated suction belt which can move over an opening which is connected to a vacuum source via a pipe. Each time a single envelope has to be taken from the pile, the suction belt with its perforations moves over the opening, so that the envelope is held onto the belt. These devices have a limited supply speed, they cannot be adjusted in a flexible manner and lead to an irregular supply distance between the envelopes. From EP 0.857.674, WO 90/11953 and US 5.417.158 it is also known to use rotating drums provided with suction openings. Also these known devices show the disadvantage that they cannot guarantee a regular supply distance between the successive products. The invention aims at a device for supplying thin objects to a conveying device in an overlapping manner which does not have the above-mentioned and other disadvantages and which has a relatively simple construction and thus is economical, but which can nevertheless supply flat objects, in particular envelopes, at a relatively high speed, in a precise manner, and thus at an invariable mutual distance. To this end, the invention relates to a device for supplying piled, thin objects, in particular envelopes to a conveying device in an overlapping manner, which device comprises a rotor which can rotate around a stator and means for driving the rotor, whereby the stator is equipped with a chamber opening in its outer perimeter which is connected to a vacuum source, and whereby the rotor is provided with openings which are temporarily situated opposite to the exit of the chamber during the rotation of the rotor, said device being characterized in that the openings at the rotor are arranged along the perimeter of the rotor and are configured in respect to the chamber in such a manner that the chamber, seen along the perimeter of the rotor, substantially can only co-operate with one opening at the same time. In this way, from the beginning of its movement, each object supplied to the conveying device, is sucked with an optimum force against the rotor, resulting in that a regular transport of the objects and consequently a constant distance between the successive objects can be guaranteed. Preferably, the device is further characterized in that the intermediate distance of the openings measured on the inner side of the rotor is equal or larger than the width of the opening with which the chamber opens in the outer perimeter of the stator. The openings may be provided according to a hole pattern and in particular form axially directed rows of holes, but the openings are preferably axially directed slots in the rotor, which makes the manufacturing easier, and as a result of which for example less deburring is required. Not only the rotational speed of the rotor can be adjusted; the stator can also be adjusted around the axis of rotation of the rotor. The means for driving the rotor may contain at least two drive belts. In this case, these belts can be driven at the same linear speed as the conveying device, so that they can ensure the conveyance of the objects from the rotor to the conveying device. In order to better explain the characteristics of the invention, the following preferred embodiment of a device for supplying thin objects to a conveying device in an overlapping manner according to the invention is described as an example only without being limitative in any way, with reference to the accompanying drawings, in which: figure 1 schematically represents a section of a device for the overlapping supply to a conveying device according to the invention; figure 2 represents the part which is indicated by F2 in figure 1 to a larger scale; figure 3 shows a side view with partial cut-out of a practical embodiment of the device according to the invention in a supply device of a printing machine; figure 4 represents a top view to a larger scale of the part which is indicated by F4 in figure 3; figure 5 is a section according to line V-V in figure 4, to a larger scale; figure 6 is a section according to line VI-VI in figure 5. The device represented in figures 1 and 2 is used for supplying envelopes 1 from a pile 2 in an overlapping manner to a conveying device 3 and mainly consists of a frame 4, a stator 5 provided upon it which is equipped with a chamber 6 opening in its outer perimeter, a rotor 7 7 surrounding the stator 5 and provided with openings 8, means 9 for driving this rotor 7 and a vacuum source 10, for example a vacuum pump, which is connected to the chamber 6 of the stator 5 by means of a pipe 11. In the given example, the stator 5 is a cylindrical body which is horizontally fixed to the frame 4 with its shaft. The chamber 6 is elongated and axially directed and it is connected to an axial duct 12 which is part of the pipe 11 on the one hand, and it opens in the outer perimeter of the stator 5 with an elongated opening on the other hand, on the top side of the stator 5. The rotor 7 is tubular and has an inner diameter which is practically equal to the outer diameter of the stator 5. In the embodiment represented in figure 1, the means 9 for driving the rotor 7 consist of a motor 13 and belts 14. The openings 8 are axially directed slots whose width, measured on the inner side of the rotor 7, is for example almost equal to the width of the above-mentioned opening with which the chamber 6 opens in the outer perimeter of the stator 5. The latter width may be equal to the intermediate distance of the openings 8, measured on the inner side of the rotor 7 and in the sense of rotation. The number of openings 8 depends on the required distance between the successive envelopes 1 on the conveying device 3 which consists of one or several endless belts 15 which are guided over wheels 16, one of which is driven by a motor in a manner which is not represented in the figures, which operates synchronously with the above-mentioned motor 13. According to a variant, the drive of the conveying device 3 may also form the above-mentioned means 9 for driving the rotor 7, which is then driven for example by means of the belts 15. Above the top part of the conveying device 3, on the frame 4, is provided a stop 17 for the pile 2 in an adjustable manner. The working of the device is as follows. The pile 2 of the envelopes 1 to be printed is put against the stop 17, so that the bottommost envelope 1 is positioned with its back part above the rotor 7, in particular above the exit of the chamber 6 of the stator 5, and rests with its front part on the conveying device 3. When the device is activated, the rotor 7 is driven by the motor 13 in the direction represented by arrow P1 in figures 1 and 2, synchronously with the conveying device 3 which is driven in the direction represented by arrow P2, such that the linear speed of the perimeter of the rotor 7 is equal to the linear speed of the conveying device 3, and a partial vacuum is created in the chamber 6 by the vacuum source 10 via the pipe 11, so that there is a suction represented by arrow P3 in figures 1 and 2. As a result, the envelope 1 which is situated at the bottom of the pile 2 is sucked against the rotor 7 as soon as an opening 8 of the rotor 7 is situated opposite the exit of the chamber 6 of the stator 5. Thanks to the suction, the envelope 1 is carried along by the rotor 7 and is pushed further forward on the conveying device 3, under the pile 2. In the same manner, a following envelope 1 is sucked up by a following opening 8 and carried along by the rotor 7 as soon as this following opening 8 is situated opposite to the exit of the chamber 6, which takes place immediately after the movement of the preceding envelope 1, as the envelopes 1 are only situated with their back parts above the rotor 7. This following envelope 1 is pushed on the conveying device 3 on top of the preceding one, so that the envelopes 1 overlap on this conveying device 3 and are situated at an invariable and fixed distance from one another with their back edges, whereby the last envelope 1 which was carried along lies each time on top. If the envelopes 1 lie too far backward in relation to the rotor 7, several successive openings 8 should carry along the bottommost envelope before it rests completely on the conveying device 3 and has thus been removed from above the rotor 7. The distance between the successive envelopes 1 depends on the distance between the openings 8 and thus on the number of openings 8 spread over the perimeter of the rotor 7. By moving stop 17, it becomes possible to handle envelopes 1 having different sizes. If every envelope 1 is sucked up and moved by a single opening 8, the distance over which a sucked-up envelope 1 is moved, will depend on the size of the exit of the chamber 6 in the outer perimeter of the stator 5. The moment at which an envelope 1 is first sucked up and moved depends on the position of the exit of the chamber 6 and may possibly be modified by rotating the stator 5 around the axis of rotation of the rotor 7. The speed at which the envelopes 1 are put on the conveying device 3 depends on the speed of the rotor 7 which is for example synchronised with the speed of the conveying device 3, and is determined by the speed of the printing machine being fed by it. Figures 3 to 6 show a more practical embodiment of the above-mentioned device. In this embodiment, the frame 4 consists of two side walls 18 and 19 which are connected by cross connections 20. The stator 5 is supported by these side walls 18 and 19 by means of horizontal rods 21 and 22 which extend this stator 5 on both sides and which are provided with one rotatable end in the side wall 18 or 19. On the rod 21, on the outer side of the side wall 18 is fixed a button 23 with which the rod 21 and thus also the stator 5 can be rotated so as to adjust the direction of the exit of the chamber 6, and with which said rod 21, once it has been adjusted, can also be locked. The above-mentioned pipe 11 between the chamber 6 and the vacuum source 10 partly extends through the rod 22. The rotor 7 is bearing-mounted with its ends around the rods 21 and 22 by means of ball bearings 24. The openings 8 are slots which are directed in the longitudinal direction of the rotor 7. The means 9 for driving this rotor 7 contain two O-belts 25 which are provided in grooves 26 on the far ends of the rotor 7 on the one hand and over wheels 27 on the other hand which are fixed on a horizontal shaft 28, next to the above-mentioned wheels 16, which is bearing-mounted with its far ends in the two side walls 18 and 19 by means of bearings 29. The belts 15 are provided around said wheels 16 on the one hand, around a reversing drum 30 which is driven directly by a motor 31. There where the belts 15 touch the reversing drum 30, they are covered by endless belts 32 which are each guided over three wheels 34 fixed on shafts 33 and a tension roller 35 which is mounted on the frame 4 in a springy manner. The shafts 33 are bearing-mounted in the side walls 18 and 19 and are situated such that a part of the belts 32 extends from top to bottom, over the reversing drum 30, and ends practically horizontally on an end of an additional conveying device with endless belts 36. The stop 17 can be adjusted above the conveying device 3 and can be moved to this end over guides 37 provided on the inside of the side walls 18 and 19, and it can be locked upon the latter by means of clamps 38. On the side of the rotor 7, auxiliary stops 39 are provided which can be moved crosswise and which can be locked in one position so as to position the envelopes 1 in the cross direction as well. On the other side, two pressure wheels 40 are provided on the stop 17 which press on the top side of the conveying device 3 in a springy manner. As represented in figures 2 and 3, a number of fingers 41 are situated at the end of the device, i.e. on the other side of the rotor 7 than the stop 17, which can be shifted over and which can be rotated around a cross rod 42, but which can be locked on this cross rod 42 by means of a tightening screw 43. This cross rod 42 has been fixed to the side walls 18 and 19 with its far ends and forms one of the above-mentioned cross connections 20, and it is situated somewhat higher than the rods 21 and 22, such that the fingers 41 are situated above these rods 21 and 22. The working of this embodiment is analogous to the working described above, with this main difference that the pile 2 is supported in a different manner and that the bottommost envelope 1, which is sucked up by the rotor 7, is moved further to the conveying device 3 by the O-belts 25 after it has been moved by the rotor 7. The pile 2 which has been positioned with its back side above the rotor 7 with the help of the stop 17 and the additional stops 39, rests on the O-belts 25 and, next to the rotor 7, on fingers 41. By means of the belts 14, the rotor 7 is driven by the conveying device 3 and, of course, synchronously with it. When a slot of the rotor 7 is situated opposite the chamber 6, the bottommost envelope 1 is sucked up, as a result of which it bends in between the O-belts 25. As soon as this envelope 1 is released again, it is conveyed further by these O-belts 25, and subsequently by the belts 15, it is turned around by the reversing drum 32 and taken up further by the belts 32 and transmitted to the belts 36. According to a variant of the above-described embodiment, the exit of the chamber 6 on the outer surface of the stator 5 does not consist of a slot but of a hole pattern, preferably an axially directed row of holes. Also the openings 8 may consist of a hole pattern instead of of axially directed slots, in particular an axially directed row of holes. The invention is by no means limited to the above-described embodiments represented in the accompanying drawings; on the contrary, such a device for supplying thin objects to a conveying device in an overlapping manner can be made in all sorts of variants while still remaining within the scope of the invention.

Claims: Device for supplying piled, thin objects, in particular envelopes (1), to a conveying device (3) in an overlapping manner, which device comprises a rotor (7) which can rotate around a stator (5) and means (9) for driving the rotor (7), whereby the stator (5) is equipped with a chamber (6) opening in its outer perimeter which is connected to a vacuum source (10), and whereby the rotor (7) is provided with openings (8) which are temporarily situated opposite to the exit of the chamber (6) during the rotation of the rotor (7), characterized in that the openings (8) at the rotor (7) are arranged along the perimeter of the rotor (7) and are configured in respect to the chamber (6) in such a manner that the chamber (6), seen along the perimeter of the rotor (7), substantially can only co-operate with one opening (8) at the same time. Device according to claim 1, characterized in that the intermediate distance of the openings (8) measured on the inner side of the rotor (7) is equal or larger than the width of the opening with which the chamber (6) opens in the outer perimeter of the stator (5). Device according to claim 1 or 2, characterised in that the openings (8) are axially directed slots. Device according to claim 1 or 2, characterised in that the openings (8) form a hole pattern and are preferably axially directed rows of holes. Device according to any of the preceding claims, characterised in that the exit of the chamber (6) on the outer surface of the stator (5) is an elongated opening which is directed parallel to the axis of the rotor (7). Device according to any of claims 1 to 4, characterised in that the exit of the chamber (6) on the outer surface of the stator (5) forms a hole pattern and preferably consists of a row of holes directed parallel to the axis of the rotor (7). Device according to any of the preceding claims, characterised in that the width of the exit of the chamber (6) on the outer surface of the stator (5) is almost equal to the distance, measured on the inside of the rotor (7) and according to the sense of rotation, between the openings (8) in the rotor (7). Device according to any of the preceding claims, characterised in that the stator (5) can be adjusted around the axis of rotation of the rotor (7). Device according to any of the preceding claims, characterised in that the means (9) for driving the rotor (7) contain at least two belts (15) which extent over this rotor (7). Device according to any of the preceding claims, characterised in that the conveying device (3) is itself part of the means (9) for driving the rotor (7). Device according to claims 9 and 10, characterised in that the conveying device (3) contains belts (15) extending over wheels (16), and in that the above-mentioned belts (15) which extend over the rotor (7) also extend over wheels (27) which are coupled to the first-mentioned wheels (16). Device according to any of the preceding claims, characterised in that it contains a stop (17) for the pile (2) which is erected above the conveying device (3). Device according to claim 12, characterised in that the stop (17) can be adjusted, so that objects (1) having different sizes can be supplied to the conveying device (3). Device according to any of the preceding claims, characterised in that the conveying device (3) contains a reversing drum (30) and an additional conveying device guided over the conveying device (3) near this reversing drum (3) to stop the objects (1) as they are turned and to subsequently take them over.

Inventors: DE BELEYR GUNTHER, DE BELEYR, GUNTHER
Applicants: DE BELEYR GUNTHER, DE BELEYR, GUNTHER
Application year: 1999
Main classification: B65H3
IPC codes: B65H3, B65H5