EP0073388B1 - Device for changing the direction of transport of letters and similar rectangular articles - Google Patents

Description

The invention relates to a device according to the preamble of claim 1. A generic device is known from DE-B-1 199 697.

For example, in postal mail distribution machines, depending on the design of the distribution conveyor routes, the mail items are transported either in the direction of their long or in the direction of their short edges. The latter has the advantage that the desired distribution capacity (in letters per unit of time) can be achieved with a lower conveying speed, since then with the same gap between the letters, instead of the length, their height is decisive for the throughput. However, because the initially stacked letters are usually pulled (separated) from the stack in the direction of their long edges, a generic device is required in this case, in which the position or the direction of movement of the letters is changed accordingly.

The «first» conveyor section of the device known from the aforementioned patent specification is an upright conveyor section, within which the mail items are guided on a sliding surface that represents the specified reference line in the direction of their long edges against a fixed stop - in their end-of-motion phase, braked by a brush roller - in order to then to be led vertically upwards in the further direction of their right-angled "further" conveyor line, ie in the direction of the short edges of the mail items. As is known in practice from the use of the device, the vertical conveying path contains fingers which are arranged at regular intervals and which grip the letter that has come in and is brought to a standstill on its lower longitudinal edge. This device can therefore only be used for synchronous transport. H. the consignments must arrive at the same leading edge distances and in a certain time relationship to the position of the fingers.

The invention has for its object to provide a generic device that allows an "asynchronous" sequence of the programs.

This object is achieved by the features mentioned in the characterizing part of patent claim 1. The subclaims contain the features of advantageous developments of the invention, for which no independent protection is claimed.

DE-A-2 743 816 discloses a device for feeding flat conveyors from a first, horizontally running, upright conveying section to a second conveying section, which extends from the first at right angles upwards, in which between the first and second conveying sections is less than 45 ° third conveyor line inclined to the first and second conveyor line is arranged. All conveyor lines work with conveyor belts, which press the conveyor pieces firmly between them, so that when transferring from one conveyor track to the next, the conveyor pieces have to be plucked out of the preceding conveyor track, which easily results in damage to the conveyor pieces. Due to the lack of displaceability of the conveying pieces in the transfer area, their positional adjustment in the target position relative to the subject of the invention is difficult.

The substantially horizontal conveying plane of all conveying lines of the device according to the invention is in terms of its problems in contrast to the predominantly vertical conveying (upright conveying) of the conveying pieces in practice, for example also with the postal conveying device known from DE-B-1 116 602.

• 1) die «erste» Förderstrecke gemäss Merkmal a) und die «zweite» Förderstrecke gemäss Merkmal b) des Patentanspruchs 1 besitzen zusätzlich ausgangsseitige Förderabschnitte, in denen die Sendungen verschiebbar mitgeführt werden,
• 2) die Förderrollen der Ablenkeinrichtung gemäss Merkmal b) des Patentanspruchs 1 erfassen die Sendungen zuerst an ihren Vorder- und dann anschliessend ihren Längskanten im Gegensatz zum gleichzeitigen Erfassen der Vorder- und Längskanten bei dieser bekannten Einrichtung.

In contrast, DE-B-1 143 656 describes a postal conveyor device for rectangular items with an essentially horizontal transport plane. This known device is used to remove mail items that are too long and flat from an entry-side (“first”) conveyor line into which the mail items enter with one of their longitudinal edges aligned with a reference surface. By means of a deflecting device consisting of conveyor rollers interacting in pairs, in this device the incoming consignments are laterally guided away in a direction parallel to the conveying direction of the input-side conveying path, which includes an acute angle of, for example, 45 ° with the conveying direction of the input-side conveying path and in which it leads further to the side - after the deflection device - a «second» conveyor line runs. This part of this known device specified herewith has the features of the device according to the invention, with the following differences:

• 1) the “first” conveyor line in accordance with feature a) and the “second” conveyor line in accordance with feature b) of patent claim 1 additionally have conveyor sections on the output side, in which the consignments are slidably carried,
• 2) the conveyor rollers of the deflection device according to feature b) of claim 1 capture the mail items first on their front and then then their longitudinal edges in contrast to the simultaneous detection of the front and longitudinal edges in this known device.

Both the displaceability of the consignments in the exit area of the «first» conveyor section (ie within the conveyor section on the exit side) as well as the staggered (consecutive) detection of the front and longitudinal edges of the consignments by the conveyor rollers of the deflection device ensure - functionally supportive - only with consignments of unequal thickness (in practice very often the case) their lateral routing with the most exact possible parallel shift to the conveying direction of the «first» conveyor line. Although this maintains the orientation of the mail items during their lateral Routing away from the entry-side conveyor line is undoubtedly of eminent importance for the functional safety of the facility according to DE-B-1 143656, no suggestion for taking these measures can be gathered from this prior publication, let alone their recommendation; Likewise, there is no concrete reference in this document to a possibility of realizing the exit of the mail items from the complete device in the direction of the short mail item edges. The mail items emerge from the known device by means of an output-side conveyor line parallel to their original input direction (into the input-side conveyor line), ie instead of essentially 90 ° in the device according to the invention, the further transport angle is approximately 0 ° in the known device; only with knowledge of the invention (retrospectively) could this known device be modified to an exit angle of approximately 90 °.

• Fig. 1 in Draufsicht und schematisch vereinfacht ein Ausführungsbeispiel einer erfindungsgemässen Vorrichtung mit weiteren Ausgestaltungen als Teil einer Briefverteilanlage;
• Fig. 2 in grösserer Darstellung und teilweise schematisch einen Ausschnitt aus Fig. 1 mit den für die Wirkungsweise der Vorrichtung charakteristischen Teilen;
• Fig. 3 eine Ansicht des ersten Förderabschnitts und der ersten Umlenkeinrichtung in Richtung des Pfeiles A in Fig. 2;
• Fig. 4 eine Abwandlung des in Fig. 3 dargestellten ersten Förderabschnitts;
• Fig. 5 eine Ansicht der ersten Ablenkeinrichtung und der zweiten Förderstrecke in Richtung des Pfeiles B in Fig. 2;
• Fig. 6 eine Ansicht der zweiten Ablenkeinrichtung und der dritten Förderstrecke in Richtung des Pfeiles C in Fig. 2;
• Fig. 7 eine schematische Darstellung der Wirkungsweise der erfindungsgemässen Vorrichtung und
• Fig. 8 in Darstellung wie Fig. 7 die Wirkungsweise einer modifizierten erfindungsgemässen Vorrichtung.

Advantageous exemplary embodiments of the invention and its developments are described in more detail below with the aid of the figures. The pictures show:

• Fig. 1 in plan view and schematically simplified an embodiment of an inventive device with further refinements as part of a mail distribution system;
• FIG. 2 in a larger representation and partially schematically a detail from FIG. 1 with the parts characteristic of the mode of operation of the device;
• 3 shows a view of the first conveyor section and the first deflection device in the direction of arrow A in FIG. 2;
• FIG. 4 shows a modification of the first conveyor section shown in FIG. 3;
• FIG. 5 shows a view of the first deflection device and the second conveying path in the direction of arrow B in FIG. 2;
• FIG. 6 is a view of the second deflection device and the third conveyor path in the direction of arrow C in FIG. 2;
• Fig. 7 is a schematic representation of the operation of the device according to the invention and
• Fig. 8 in representation like Fig. 7, the operation of a modified device according to the invention.

In Fig. 1, the mail items to be processed (letters) 1 are initially in the stack of a separator 2, through which they are individually pulled off to the right in the direction of their long edges and fed upright to a first conveyor line 10. This runs in a first direction and contains at its exit a first conveyor section 10a, in which the mail items are not carried rigidly in the usual manner, but are displaceable, and a conveyor device 10b in front of them.

The task of the conveyor 10b is to guide the mailpieces 1 in the first direction I in such a way that their plane ultimately lies essentially horizontally and that one of the long edges moves along a predetermined reference line 11 before entering the conveyor section 10a. Their design therefore depends on the original position in which the mail items enter the device.

In the exemplary embodiment, the conveying device 10b contains a straightening section 3, in which the mail items entering on edge are aligned with their lower long edge at a reference plane 4, and a turning section 5, in which the mail items are recorded immovably and by a predetermined one, in the plane of the mail items and axis parallel to conveying direction I can be turned by 90 °. They are then such that their original lower edge now moves along the reference line 11.

A device with the properties of the straightening section 3 is known, for example, from the above-mentioned DE-B-1 116 602. 1 consists of a first endless belt 6, which is guided around a vertical roller 7 and a horizontal roller 8, and an endless belt 6 ', which is adjacent to the former, which is about a vertical roller 7' and one under the Roll 8 lying horizontal roll is guided. In principle, this turning route is known from DE-B-1 234 629.

The first conveyor section 10a is explained below with reference to FIGS. 2 to 4. This is followed by a first deflection device 20 with conveyor rollers 21 and 22 (with associated counter-rollers) interacting in pairs, which detect the mail items 1 at the front edge and laterally in a second direction II from the first conveyor section 10a with parallel displacement to the conveying direction of the supplying "first" conveyor line Lead away, which includes an acute angle a <45 ° with the first direction I.

Likewise, in the second direction II, a second conveyor line 30 runs, from which the mail items that are carried away are detected and the output of which forms a second conveyor section 30 a, in which the mail items are displaceably carried.

Finally, the device according to the invention contains a second deflection device 40 with conveyor rollers interacting in pairs (roller 23 with associated counter-roller), which capture the mail items at the leading long edge and laterally lead away from the second conveyor section 30a in the further direction 111, which are aligned with the first direction I encloses an angle β (see also FIG. 7) of essentially 90 ° - which achieves the desired change in the direction of movement of the mail items.

1 shows, in a further embodiment of the invention, a third conveyor section 50 ', a delay device 60 and a conveyor device 70, the purpose of which is explained below.

2, 7 and 8, some mail items 1 are shown in positions characteristic of the mode of operation of the device, wherein a small and a large size mail item is shown as if the mail items were transparent.

As already mentioned, the task of the conveyor section 10a is to now carry the mail items 1, which have been brought along with a long edge along the reference line 11, so that they can be moved, i.e. so that they can be moved by an additional external force deviating from the previous conveying direction I or the corresponding conveying speed. In the exemplary embodiment of the invention shown, this is achieved by the following configurations:

According to FIGS. 2 and 3, the conveyor section 10a contains a lower conveyor belt 13, which is guided around a driven roller 12 and on which the mail items 1 rest. An upper belt 15, which is guided around a roller 14, runs over it at the same speed, in such a way that it exerts little or no pressure force on the mail items. According to FIG. 3, this is achieved in that the belt 15 extends upwards from a common support roller 16 at a small angle with respect to the belt 13.

Fig. 4 shows a modification in which the belt 15 'is guided with the aid of deflection rollers 17 and 18 and the roller 14' so that it runs parallel to the conveyor belt 13 at a short distance. Although there is generally no contact between the belt 15 'and the mail items, this belt also increases the security of entrainment in the conveying direction I by generating or maintaining a corresponding air flow. In the embodiment according to FIGS. 2 and 3, it is expedient to attach a guide surface 19 over the uncovered end of the conveyor belt 13.

The first deflection device 20 contains a plurality of driven conveyor rollers which interact in pairs and which are aligned in accordance with the second conveying direction II. At least two pairs of conveyor rollers 21 and 22 are arranged in the conveying path of the mail items 1 in such a way that they essentially simultaneously detect the front edge of the mail items being brought up. In addition, at least one further pair of conveyor rollers 23 are arranged for engagement on the long edge so that their detection area (i.e. the line on which the rollers touch) is at a small lateral distance d from the reference line 11. If the formats of the mailpieces to be processed are very different, the pairs of conveyor rollers mentioned can be supplemented by further pairs, of which the roller 24 is shown in FIG. 2 with dashed lines.

In contrast to the device known from DE-PS 1 199 697, the front edge of the consignment 1 does not run here against a fixed stop, but instead moves into the detection range of the two pairs of the first conveyor section 10a during its movement in the conveying direction I Conveyor rollers 21 and 22, the peripheral speed of which in the second direction II in any case has a considerable speed component in the first direction 1. It is possible to select this conveying speed in such a way that the named speed component is equal to the original conveying speed in the first direction 1. In general, however, the conveying speed of the first deflecting device 20, like that of the second deflecting device 40, is selected empirically in such a way that overall an optimal operating behavior results.

After the detection of its front edge by the conveyor roller pairs 21 and 22, the consignment 1 is forcibly moved laterally out of the conveyor section 10a and with a parallel displacement to the original conveying direction in the direction II. Shortly thereafter, the originally lower long edge also comes into the detection area of the conveyor rollers 23 (or 23 and 24), which support the forwarding of the mail item into the second conveyor line 30.

2 and 5, a conveyor belt 33 guided around rollers 31 and 32 and a belt 37 guided above it by rollers 34, 35 and 36. The latter rollers are arranged in such a way that the incoming mail items are initially recorded relatively rigidly in the region of the roller 35, while they are displaceably carried along in the region of the outlet forming the second conveyor section 30a.

The second deflection device 40 consists of three pairs of conveyor rollers 41, 42 and 43 which are arranged such that their detection area (i.e. the connecting straight line of the centers of their contact lines) runs essentially parallel to the reference line 11. As soon as the consignment 1 with its leading long edge comes into this detection area, it is laterally pulled away from the second conveying section 30a by a parallel displacement to the original conveying direction in the third direction 111 by the aforementioned conveying rollers.

FIG. 2 shows a third conveyor section 50, which also continues in the third direction III in continuation of the path of the mail items carried away by the deflection device 40 and, according to FIG. 6, consists of two conveyor belts 53 and 54 guided around rollers 51 and 52. These conveyor belts are guided with the aid of a support roller 55 in such a way that the mailpieces fed in are rigidly recorded and also continued.

Although the described two-way deflection of the mail items is generally sufficient to solve the task at hand, it can be advantageous under particularly unfavorable operating conditions - in particular with regard to the nature of the mail items - between the second conveying section 30a and the second deflection device 40 according to FIG. 8 to insert a further deflection device 20a, with pairs of conveyor rollers, which capture the mail items at the leading long edge and laterally move them out of the second conveyor section, parallel to the original conveying direction, in a direction Ila which lies between the directions II and III. The direction Ila thus includes an angle y with the original conveying direction, for which the relationship a <y <β applies. On the deflection device 20a a further conveyor section would then follow, in which the consignments are slidably carried in the direction Ila.

It can also be advantageous to provide a stop surface 45 in the region of the second deflection device 40 or further deflection device 20a. It is arranged at the position where the short front edge of the mail items 1 is when its long edge is in the detection area of the conveyor roller pairs 41 to 43.

This stop may prevent particularly heavy mail items or those with an unfavorable position of the center of gravity from reaching an undesired position due to inertial forces. In a further embodiment, it is possible to design this stop surface as a conveyor belt 48 guided around rollers 46 and 47.

• An die dritte Förderstrecke 50' (Fig. 1) kann sich an die Stützrolle 55 ein dritter Förderabschnitt 50a anschliessen, in welchem die Sendungen ein weiteres Mal verschiebbar mitgeführt werden. Sie gelangen sodann in den Erfassungsbereich derhier aus weiteren Förderrollen-Paaren 61, 62 und 63 gebildeten - Verzögerungseinrichtungen 60, wobei die Fördergeschwindigkeit kleiner ist als die bisherige Fördergeschwindigkeit in der dritten Förderstrecke. Dadurch laufen die Sendungen jeweils so auf, dass ggf. eine weitere Ausrichtung erfolgt. An die Verzögerungseinrichtung 60 schliesst sich die normale weitere Fördereinrichtung 70 mit gleicher Fördergeschwindigkeit an.

By using the device according to the invention in accordance with the functional groups described so far, it is achieved that the mail items fed in the direction of their long edge emerge quietly and without interference in the direction 111 perpendicular thereto, their short edges generally being parallel to this direction with sufficient accuracy. In the case of particularly unfavorable operating conditions or if a particularly precise alignment of the mail items is required for certain reasons, the device can be designed in such a way that the following functional groups follow in the conveying direction 111:

• At the third conveyor section 50 '(FIG. 1), a third conveyor section 50a can be connected to the support roller 55, in which the consignments are slidably carried once more. They then reach the detection area of the deceleration devices 60 formed here from further conveyor roller pairs 61, 62 and 63, the conveyor speed being lower than the previous conveyor speed in the third conveyor section. As a result, the consignments each accumulate in such a way that further alignment is possible. The normal further conveying device 70 connects to the delay device 60 with the same conveying speed.

In a further modification, instead of the delay device 60 in the second deflection device 40, the circumferential speed of the conveyor roller pairs 41 to 43 can be chosen to be lower than the conveying speed in the second conveying direction II.

It goes without saying that the conveyor rollers 21 to 24, 41 to 43 and 61 to 63 of the deflection devices 20, 20a and 40 or the deceleration device 60 must have a surface with a high coefficient of friction and that they can adapt to different letter thicknesses in a known manner . The latter can e.g. can be achieved in that the shaft of the respective lower roller of a pair of rollers is rigid and the shaft of the upper roller is mounted on a rocker arm. It may also be sufficient if the upper rollers are provided with a thick, elastic covering when they are firmly supported. In the case of the roller pairs 41 to 43 and 61 to 63, the respective lower rollers can be mounted on a common shaft and the upper rollers individually on rockers or - if they have a thick elastic covering - also on a common shaft.

Although the rollers mentioned are generally driven so that the rollers belonging to one and the same deflection device have the same peripheral speed, it would also be possible within the scope of the invention, for. B. to drive the pairs of rollers 21 to 24 of the first deflection device 20 in adaptation to certain working conditions with coordinated, slightly different peripheral speeds.

Claims (8)

1. Device, for changing the direction of movement of letters and similar rectangular consignments (1) entering in the direction of their long edges in such a manner that they issue in the direction of their short edges, with a feeding first conveyor path (10), which extends in a first direction (I) and in which the consignments are moved with one of their long edges along a predetermined reference line (11) and with a further conveyor path (50) leading away in a further direction (III) including an angle substantially of 90° with the first direction, characterised by the following features:

a) the first conveyor path (10) at the exit side displays a first conveyor portion (10a), in which the consignments are guided along displaceably and the plane of which lies substantially horizontally,

b) a first deflecting equipment (20) with conveyor rollers (21... 24), which co-operate in pairs and seize the consignments at their front edge and subsequently at their longitudinal edge and conduct them away laterally in a second direction (II) out of the first conveyor portion (10a) with displacement parallel to the conveying direction of the first conveyor path (10), the second direction (II) including with the first direction (I) an acute angle (a), which is smaller than or equal to 45°,

c) a second conveyor path (30) for the seizing of the consignments which are conducted away, which extends in the second direction (II) and the exit of which forms a second conveyor portion (30a), in which the consignments are guided along displaceably,

d) of the conveyor rollers (21... 24),

1) at least two pairs (21, 22) are so arranged in the conveying route that they seize the front edge of the consignments substantially simultaneously and

2) at least one pair (23, 24) is so arranged for engagement at the long edge that its catchment range displays a small lateral spacing (d) from the reference line (11), and

e) a second deflecting equipment (40) with further conveyor rollers (41... 43) which co-operate in pairs and seize the consignments at their long edge and conduct them away laterally in the further direction (III) out of the second conveyor portion (30a).

2. Device according to claim 1, characterised thereby, that inserted between the second conveyor portion (30a) and the second deflecting equipment (40) are:

a) a further deflecting equipment (20a) with conveyor rollers, which co-operate in pairs and the catchment range of which extends substantially parallelly to the predetermined reference line (11) and which seize the consignments (1) at their long edge and conduct them away laterally out of the second conveyor portion (30a) in a third direction (Ila), which lies between the second direction (II) and the further direction (III), and

b) a further conveyor portion, in which the consignments are guided along displaceably in the third direction.

3. Device according to claim 1 or 2, characterised thereby, that the first conveyor portion (10a) and the second conveyor portion (30a) each contain a respective conveyor belt (13 or 33), on which the consignments (1) rest by their area, and a respective second belt (15 or 37), which is so conducted above the conveyor belt while covering a part of its length that it exerts no or only a small contact pressure force on the consignments.

4. Device according to one of the claims 1 to 3, characterised thereby, that an abutment surface (45) is arranged in the region of the second deflecting equipment (40) and namely at the place, at which the front edge of the consignments (1) is disposed when their long edge gets into the catchment range of the conveyor rollers (41... 43) leading away laterally.

5. Device according to claim 4, characterised thereby, that the abutment surface is formed by a conveyor belt (48).

6. Device according to one of the claims 1 to 5, characterised by

a) a third conveyor path (50') adjoining the exit of the further conveyor path (50) and with a third conveyor portion (50a), in which the consignments are guided along displaceably,

b) a delaying equipment (60) following the third conveyor portion (50a) and with conveyor rollers (61... 63), which co-operate in pairs and the catchment range of which extends perpendicularly to the further direction (III) and the conveying speed of which is smaller than the conveying speed in the third conveyor path (50').

7. Device according to claim 4, characterised thereby, that the peripheral speed of the conveyor rollers (41... 43), co-operating in pairs, of the second deflecting equipment (40) is smaller than that component of the conveying speed in the second conveying direction (II), which is referred to the further direction (III).

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