EP0704255A2 - Device for reversing the transport direction of flat mail objects - Google Patents

Abstract

The device has a transportation roller (3) located between the feed and delivery conveyor systems (1,2). Two extended fence elements (4,5), parallel to each other, are located tangentially to the transportation roller. The transportation roller and fence elements are rotatable around a common axis (A) independently of each other in the region between the conveyor systems. Consequently, flat parcels (3a) fed through the first conveyor system are frictionally directed between one fence element and the transportation roller.

Description

The present invention relates to a device for reversing the transport direction of flat mail items for mail distribution systems.
In mail distribution systems, in which flat mail items are supplied with character recognition and marking devices in order to distribute the mail items in accordance with various information applied to their surface, there is a problem in that a part of the mail items is transported in the conveying means in such a way that the information provided Surface is not arranged in the processing position opposite the character recognition and identification means. A shipment that is not in the processing position can be brought into the working position by rotating the shipment about the longitudinal axis and / or the vertical axis. A problem that arises with such rotations is that the gaps between the consignments or the distances between the front or rear edges of the consignment are changed by the operation of the rotation, possibly even overlapping of consignments, which can lead to blockages and malfunction of the system.

A device for reversing the direction of flat mail items is already known from DE 43 15 053, with conveying means for feeding the mail items at a first speed and further funding means for removing the mail items at a second speed, the first conveying means for feeding the mail items at a first predetermined speed in the second funding for receiving the Consignments and detection means for determining the point in time at which the rear edge of a consignment that has left the first conveying means is provided. Each shipment is picked up in the second conveyor at the first predetermined speed and, as soon as its rear edge has left the first conveyor, braked according to a predetermined speed profile. The direction of conveyance is then reversed and the shipment is accelerated to a second predetermined speed. Third funding is provided for receiving the mail items from the second funding at the second predetermined speed, the sediments in the first, second and third funding being guided non-positively at all times.

The object of the present invention is to provide a device with which mail items can be rotated quickly and safely about their vertical axis.

According to the invention the object of the features of independent claims 1 and 2 is achieved, advantageous embodiments of the invention are contained in the subclaims and the description. It is particularly advantageous in the device according to the invention that the consignments are guided smoothly and safely within the device. The programs always remain recorded and are never left to their own devices. This achieves a high degree of precision in the movement of the mail items and prevents mail run disruptions. This device brakes and accelerates the mail gently. The device is also particularly space-saving. The mail items are rotated in such a way that the gaps in the mail flow before and after the mail items are rotated are the same, or not the mail item gaps, but the distances between the front or rear edges of the items before and after the rotation remain constant.

Figur 1

eine Prinzipdarstellung einer erfindungsgemäßen Vorrichtung in Draufsicht,

Figur 2a und 2b

eine Darstellung der zeitlichen Verhältnisse bei langen und kurzen Sendungen,

Figur 3

ein Schnittbild X-X gemäß Figur 1,

Figur 4

eine Prinzipdarstellung einer weiteren erfindungsgemäßen Vorrichtung,

Figur 5

eine Prinzipdarstellung eines alternativen Antriebsystems für eine erfindungsgemäße Vorrichtung.

The invention is explained in more detail below with reference to FIGS. 1 to 5. It shows

Figure 1

1 shows a schematic diagram of a device according to the invention in plan view,

Figure 2a and 2b

a representation of the temporal relationships for long and short programs,

Figure 3

2 shows a sectional view XX according to FIG. 1,

Figure 4

a schematic diagram of a further device according to the invention,

Figure 5

a schematic diagram of an alternative drive system for a device according to the invention.

In the device according to the invention shown in its basic structure in FIG. 1, the mail items 3a are first transferred from the feeding conveying means 1 to the device for reversing. The conveying means 1 usually consist of conveyor belts, between which the items are moved upright. The reversing device essentially has two fence elements 4, 5 arranged symmetrically to one another, between which a transport roller 3 is arranged. The transport roller and the fence elements are arranged in an area between the conveying means 1 and the discharging conveying means 2 so as to be rotatable about an axis A.

The fence elements 4, 5 are arranged essentially parallel to one another and tangential to the transport roller. Each fence element forms an essentially linearly elongated and angled sliding surface for the mail items. The two fence elements are point symmetrical to each other arranged to the axis of rotation A that together they form a transport channel, the cross section of which decreases in the region of the angled part of each fence element.

Transport roller 3 and fence elements 4, 5 can be rotated about the same axis A. Each fence element consists of a section with a bend and a section which is substantially linear. Seen from the common axis A of the transport roller and fence element, the angled section of each fence element extends less far than the linear section of the respectively opposite fence element. The linear section of a fence element serves as a receiving surface for the mail items during the supply and as a removal area during the removal of the mail items. For this purpose, it is advantageous that this part protrudes into the area of the feeding or discharging conveying means when the mail items are picked up or removed in such a way that secure pick up or removal of the mail item is ensured. When using conveyor belts 1a, 2a, between which the mail items are moved upright, the end region of this section preferably projects above the conveyor belts 1a and 2a. The fastening of all rollers and conveyor belts projecting into the radius of the fence elements 4, 5 is designed such that no collisions with the fence elements 4, 5 occur.

The angled section of each fence element is used to transfer mail items for which no reversal of the transport direction is provided to the conveying means 2 at undiminished speed. From the angled section of each fence element, such a continuous mail is directed against the linear section of the opposite fence element, from which it is slidably transferred to the conveying means 2.

The transport roller 3 is arranged between the two fence elements 4 and 5 such that a flat consignment can be guided non-positively between the transport roller 3 and a fence element 4, 5. This essentially requires the selection of a suitable distance between the transport roller and the fence element as well as resilient sliding surfaces 7 in the area of each fence element in which the mail items between the fence element and the transport roller are non-positively guided.

In the operation of the device according to the invention, a distinction must be made between two cases.

Case 1:

If the shipment is not to be rotated about the vertical axis, it is transported by the transport roller 3 to the discharging conveying means 2 at an undiminished speed. The transport roller 3 is operated at a speed that is adapted to the feed speed of the mail items. The letter transported between the transport roller 3 and the fence 4 is thereby moved from the linearly elongated part of the fence 4 to the angled area and directed in the direction of the opposite linear section of the fence 5.

Case 2:

If the shipment is to be rotated about its vertical axis, the fence elements rotate through 180 ° around the axis A. The rotation begins at the earliest as soon as the rear edge of the shipment has left the conveying means 1 and this has been determined by detection means not shown in FIG. 1. While this 180 ° rotation is carried out, the speed of the transport roller is negated. The consignment is then moved by the transport roller along the linearly elongated part of the fence 4 and, after completion of the rotation, is transferred to the conveying means 2 smoothly. As soon as the shipment loses contact with the transport roller 3, the latter becomes Reverse speed again to be ready for the recording of the next program. The contact between the shipment and the transport roller is monitored by detection means not shown in FIG. 1. The following consignment may already have left the funding 1 in part, that is, protrude into the swivel range of the fence elements when the 180 ° rotation has been completed. This enables a reduction in the smallest safely processable shipment gap.

In FIG. 1, C denotes a possible trajectory of the rear edge of the consignment during the turning process. The deviation from a circular path around the axis A results from the movement of the item between the fence element 4 and the transport roller 3 that is carried out during the rotary movement.

FIG. 2 illustrates the dynamic processes that typically occur when the device is operated. The device can process mail items of different lengths. Shipment lengths between 135 mm and 295 mm are assumed as an example; the gaps between the continuously fed items are, for example, 100 mm each at a feed speed of 3 m / s. Figure 2a shows the case of a short shipment. At time t1, the 180 ° rotation is initiated. At this point, the shipment is already firmly recorded by the transport role. At the time t2 = t1 + 37 ms, the turning process is completed and the mailing is integrated into the mailing stream without having changed its relative positions.

Figure 2b shows the case of a long shipment. At time t1, the rotation is initiated, which in turn lasts 37 ms.

wobei V die Transportgeschwindigkeit und l_min die Länge des kürzesten zu verarbeitenden Briefes bezeichnet. l_klem,min ist die für einen sicheren Kontakt zwischen Transportrolle und Sendung mindestens erforderliche Klemmlänge, vgl. Figur 2a. Bei einer längeren Sendung der Länge l ist die Klemmlänge l_klem größer, nämlich $${\text{l}}_{\text{klem}}{\text{= l - l}}_{\text{min}}{\text{+ l}}_{\text{klem,min}}\text{.}$$

The two representations 2a and 2b show that, in the example under consideration, t2 must be selected such that at this point in time the left edge of the letter is 111 mm further away from the axis of rotation A than the right. This way from 111 mm corresponds to a rotation time of 37 ms at 3 m / s. In general, the following applies to the relationship between the length of the shipment and the time available for 180 ° rotation: $${\text{t}}_{\text{180}}\text{=}\frac{{\text{l}}_{\text{min}}{\text{- l}}_{\text{klem, min}}}{\text{V}}\text{,}$$

where V denotes the transport speed and l _min the length of the shortest letter to be processed. l _{klem, min} is the minimum clamping length required for secure contact between the transport _roller and the consignment, cf. Figure 2a. In the case of a longer shipment of length l, the clamping length l _{klem is} larger, namely $${\text{l}}_{\text{stupid}}{\text{= l - l}}_{\text{min}}{\text{+ l}}_{\text{klem, min}}\text{.}$$

FIG. 3 shows a sectional view along the length X-X in FIG. 1. The device is then mechanically driven by two electric motors 8, 9, which are arranged on the same geometric axis A. The torque of the motor 8 is passed on to the fence elements 4, 5 and to the transport roller 3 via a hollow shaft 10 which surrounds a shaft 11. It is advantageous to avoid unnecessary moments of inertia: the fence elements 4, 5 can be designed as a wire frame.

A further embodiment of the invention is shown in FIG. Instead of a single transport roller, two rollers 12 and 13 are provided which can be rotated about an axis B. The rollers 12 and 13 are advantageously provided with an endless belt 14 in order to ensure better guidance of the item 3a. Compared to the embodiment according to FIG. 1, the letters are gripped earlier by one of the transport rollers 12, 13, so that the rotary movement can be started earlier and may take a long time. Therefore, with This arrangement advantageously extends the time available for a 180 ° rotation of the fence elements. In this embodiment too, the transport rollers 12, 13 are each independently rotatable about their axes of rotation 6, 6 'with respect to the rotational movement of the fence elements 4 and 5 about the common axis of rotation B.

FIG. 5 shows a further embodiment of the mechanical drive for the device according to the invention. The torque of the motor 14 is then transmitted via the shaft 16 or the motor 15 via the drive belt 17 to the hollow shaft 18 to the transport roller or the fence elements. As in FIG. 3, the shafts are supported in bearings 19.

Claims (7)

Device for reversing the transport direction of flat mail items with first feeding and second discharging conveying means (1, 2), characterized in that
that a transport roller (3) is arranged in the area between supply and discharge conveying means (1, 2),
that tangential to the transport roller (3) and substantially parallel to each other two elongated fence elements (4, 5) are arranged, the transport roller (3) and the fence elements (4, 5) in the area between the conveying means (1, 2) independently of one another are rotatable about a common axis A and wherein flat items (3a) fed by first conveying means (1) are guided in a force-locking manner between each fence (4, 5) and the transport roller (3). Device for reversing the transport direction of flat mail items with first feeding and second discharging conveying means (1, 2), characterized in that two or more transport rollers (12, 13) are arranged in the area between feeding and discharging conveying means (1, 2), that two elongate fence elements (4, 5) are arranged tangentially to the transport rollers and essentially parallel to one another, the transport rollers (12, 13) having axes of rotation (6, 6 '), the fence elements (4, 5) and the transport rollers (12 , 13) are arranged rotatably about a common axis B, the transport rollers (12, 13) and the axes of rotation (6, 6 ') and the fences about the axis B in each case are independently rotatable, and wherein the flat items fed by the conveying means (1) are guided between each fence element (4, 5) and the transport rollers (12, 13) in a force-locking manner. Apparatus according to claim 1 or 2, characterized in that the fence elements (3, 4) form a transport channel in such a way that, if a reversal of the transport direction is provided for a mail item, the mail item is transferred to the conveying means (2). Device according to Claims 1 to 3, characterized in that each fence element (4, 5) has a resilient sliding surface (7) in the area in which the mail items are guided between the fence element (4, 5) and the transport roller (3). Device according to claims 1 to 4, characterized in that the fence elements (4, 5) are attached to a hollow shaft (10, 18) and the drive of the transport roller (3) or the transport rollers (12, 13) by one in the hollow shaft (10, 18) axially arranged shaft (11, 16). Device according to claim 2, characterized in that the two or more transport rollers are provided with an endless belt connecting them. Method of operating a device according to claims 1 to 6, characterized in that, if a reversal of the transport direction is provided for a shipment, the fence elements (4, 5) rotate essentially by 180 °, which begins at the earliest as soon as the rear edge the consignment has left the first feeding conveyor (1) and that during this rotation the rotational speed of the transport roller (3) or Transport rollers (12, 13) is negated in such a way that after completion of the rotation of the fence elements (4, 5) there is a smooth transfer to the second conveying means (2) and that as soon as this shipment loses contact with the transport roller (3), the rotational speed is negated in such a way that a subsequent consignment can be fed into the device.

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