WO2007045492A1

WO2007045492A1 - Aiding a filling of a sack with mail items

Info

Publication number: WO2007045492A1
Application number: PCT/EP2006/010140
Authority: WO
Inventors: Walter Rosenbaum; Uwe Neitzel; Daniele Di Benedetto
Original assignee: Siemens Aktiengesellschaft
Priority date: 2005-10-21
Filing date: 2006-10-20
Publication date: 2007-04-26

Abstract

A method and system for aiding a filling of a mail sack (19) with mail items (14) cause the mail items (14) to fall into a receiving opening (31) of an intermediate guide device (13). Within the intermediate guide device (13), the trajectory of the falling mail items is influenced (14) to obtain a predetermined orientation of the plane of the mail items (14) during their descent from an output opening (32) of the intermediate guide device (13) towards the mail sack (19) positioned below said output opening (32).

Description

AIDING A FILLING OF A SACK WITH MAIL ITEMS

The various embodiments described herein relate generally to a mail processing system. More particularly, these embodiments relate to a method, a system and an apparatus for aiding a filling of a sack with mail items according to the preamble of claims 1 to 3, respectively.

Each day postal services process mail items for delivery to millions of individual domestic addresses. As used throughout this application, mail items refer to letters, magazines, books, flat bundles and packets and other such flat items. Before mail carriers begin to walk through or drive through their delivery routes, a mail processing system, at a processing site, sorts, through sortation means, all mail items for the carriers and prepares the sorted articles for delivery to a multitude of domestic addresses. A carrier's responsibility includes putting all of these articles into an appropriate sequence and in appropriate containers for efficient delivery to the domestic addresses. The mail processing system is highly automated to handle the amount of daily articles.

In current state of the art processing mail systems, processing automatic sortation platforms of postal or courier mail items are frequently used to directly channel a fairly heterogeneous mix of such mail items into sacks or bags for transport between sites. Such heterogeneous, automatic sortation is typically called "multisorting".

The mail sacks or bags, while having the practical advantage of being simple and cheap containers to sort and to store mail items, when empty, have, unfortunately, the drawback of not being, in general, densely tillable to their volume capacity. This happens especially when the mail items are discretely ejected from the sortation platform directly into the mail sack where the ejected mail items cluster loosely at odd angles to one-another. This jumble of mail items, without any stacking, preempts efficient use of the volume capacity of the mail sack.

The immediate operational impact of "living with the problem" of only partially filled mail sacks is the increase in logistic costs for additional transportation space required due to the inflated number of mail sacks required for a given mail volume. In alternative to mail sacks, in order to achieve a more space efficient method for transporting large mail items, trays are also used as containers for the mail items and pieces. When layered one upon the other, large mail items and pieces can be efficiently stored in mail trays which can be, in turn, efficiently transported in layered stacks.

However, utilizing hard sided containers like mail trays requires special filling techniques and additionally the trays need to be built up into pallet loads for efficient transportation. Accordingly, although mail trays are widely used in postal operation such as U.S. Postal Service, they have made scant inroads in express courier operations where flexibility and responsive service is key.

The advantage of mail sacks over mail trays is that sacks can be transported individually and do not need to be built up in pallet loads. Moreover, the returned mail sacks when redistributed around the postal network take-up much less shipping and storage space then the equivalent tray containerization.

Alternatively, a compromise solution, between the usage of sacks and trays, is the usage of large tubs or soft sided hampers to receive the mail items. However, although such hamper containers are in general widely dimensioned to facilitate filling, their transport often requires additional repackaging of their contents. In addition, the weight of such large load tubs can crush smaller items at the bottom of the hamper.

There is, therefore, a need for a technique for improving the filling rate of mail sacks with generally diverse mail items. This need is particularly compelling if rising energy prices are taken into account.

Accordingly, one aspect involves a method and a system for aiding a filling of a sack with mail items in which mail items are caused to fall into a receiving opening of an intermediate guide device. According to this aspect, the trajectory of the falling mail items is influenced to obtain a predetermined orientation of the plane of the mail items during their descent from an output opening of the intermediate guide device towards the mail sack positioned below said output opening. Another aspect of the present invention involves an apparatus for aiding a filling of a mail sack with mail items, comprising an intermediate guide device configured to receive ejected mail items conveyed by conveying means into a receiving opening of an intermediate guide device. According to this aspect, the intermediate guide device comprises means for influencing the falling trajectory of the mail items to obtain a predetermined orientation of the plane of the mail items during their descent from an output opening of said intermediate guide device towards the mail sack positioned below said output opening.

According to one embodiment, the intermediate guide device may comprise at least three lateral sides, beside the receiving opening at its top side and the output opening at its bottom side.

According to a further embodiment of the invention, the opening of the mail sack may be preferably arranged along the output opening of the intermediate guide device.

According to a further embodiment of the invention, the output opening may particularly comprise trap doors.

According to a further embodiment of the invention, means for influencing the falling trajectory of the mail items may advantageously comprise an inclined surface whose axis is inclined with respect of an horizontal line to control the flow of mail items towards the mail sack via the output opening of the intermediate guide device.

According to a further embodiment of the invention, the receiving opening of the intermediate guide device may preferably have a length greater the length of the opening of the mail sack.

The proposed embodiments enable a controlled falling down of sorted mail items to be sacked into a mail bag.

Thus, the proposed embodiments allow an optimized mail sack filling with mail items so that the capacity filling of each mail sack is, on average, improved significantly. Conveniently, via the proposed embodiments, fewer sacks are required to transport multisorted items between sites.

Thus, with the proposed embodiments, the number of sacks required per a given volume of mail is reduced with the corresponding benefit in transportation cost while the order of mail pieces is in general retained which can reduce subsequent manual handling.

As a consequence, with the proposed embodiments, the logistics of mail items is rendered more efficient and less expensive.

These and other aspects, advantages and novel features of the embodiments described herein will become apparent upon reading the following detailed description and upon reference to the accompanying drawings. In the drawings, same elements have the same reference signs. In the following list of figures: Figure 1 depicts a schematic illustration of one embodiment of a system for aiding a filling of a mail sack with mail items; Figure 2 depicts a schematic illustration of a further embodiment of a system for aiding a filling of a mail sack with mail items; and Figure 3 depicts the top and lateral views of the apparatus for aiding a filling of a mail sack with mail items shown in Figure 2.

Figure 1 depicts a mail sack or a bag 19 for receiving mail items 14. An intermediate guide device 13 is arranged between sortation means 11 and the mail sack 19. The intermediate guide device 13 may be a frame, a tray or a receptacle. Figure 1 depicts a conveyor belt which may be one of the possible elements constituting the sortation means 11. Conveying means 12 may be arranged between the guide device 13 and the conveyor belt 11 for allowing the sliding of the sorted mail items 14 towards the intermediate guide device 13, causing the mail items 14 to fall into such intermediate guide device 13. The conveying means 12 may be a chute, a slide or a mechanized channel. The intermediate guide device 13 comprises at least three lateral sides 16, 17, 18. The top and the bottom sides of the intermediate guide device 13 are open to allow the passage of the sorted mail items 14 towards the mail sack 19. The top and the bottom sides of the intermediate guide device 13 are hereinafter called receiving and output opening 31, 32 respectively (see Figure 3). Optionally, the output opening 32 of the intermediate guide device 13 may be provided with trap doors 15a, 15b. In further embodiments according to the present invention, at the output opening 32 of the intermediate guide device 13, the trap doors 15a, 15b may not be present or, alternatively, other types of closing means may be present. The mail sack 19 is arranged to receive the sorted mail items 14 from the intermediate guide device 13 by having its mouth kept open along the lateral sides 16, 17, 18 of the intermediate guide device 13. The mail sack 19 may be held open and aligned by a simple stationary frame, not shown.

In operations, the mail items 14 to be sacked are sorted with high quality of alignment, typically called "stacking", by sortation means 11 in coordination with conveying means 12, into the receiving opening 31 of the intermediate guide device 13. The conveying means 12 is frequently referred to in the literature as a chute however in further embodiments according to the present invention other form factors are possible. Within the intermediate guide device 13, the falling trajectory of the mail items 14 is influenced, particularly, by the second side 17 of the intermediate guide device 13 so as to obtain, with respect of prior art sacking methods, a more controlled descent of the mail items 14 to the mail sack 19 via the output opening 32. The controlled descent of the mail items is obtained by having a predetermined orientation of the falling trajectory of the plane of the mail items 14. The predetermined orientation may be, in a first embodiment, a substantially horizontal orientation. Considered that at least one of the lateral sides 16, 17, 18 may have a vertical orientation, such substantially horizontal orientation of the plane of the mail items 14 is substantially defined as the perpendicular to such, at least one, vertically orientated lateral side 16, 17, 18. In further embodiments of the present invention, the predetermined orientation is an inclined orientation, forming an acute angle, greater than 45 degrees, with, at least one, vertically orientated lateral side 16, 17, 18. In prior art sacking methods, instead, mail items 14 may typically fall with an orientation of their plane substantially vertical.

The mail sack 19 can be easily removed by an operator when full and replaced without disturbing the intermediate guide device 13, for example, through the above mentioned stationary frame.

In the embodiment of Figure 1, where the traps doors 15a, 15b are present at the output opening 32 of the intermediate guide device 13, when the intermediate guide device 13 has reached a "full" condition, the trap doors 15a, 15b open, under the intermediate guide device 13, thus allowing the stacked mail items 19 to fall into the mail sack 19 from the output opening 32. Control of trap doors 15a, 15b may be performed via direct measurement of the guide level of filling or via indirect accounting using mail item thickness. Mail item thickness may be measure when mail items are inputted to the sortation means 11 or while they transit on the sortation means 11 or on the conveying means 12. When a given level of filling has been reached in the intermediate guide device 13, as ascertained by direct measurement or by indirect accounting, the traps doors 15a, 15b are triggered to open causing the accumulated mail items 14 in guide device 13 to be released to fall with a controlled orientation into the below mail sack 19. The process of filling the sack 19 via the trap doors 15a, 15b can be continued until the mail sack 19 reaches a given volume or weight where upon an operator may be signaled to remove and replace such filled sack 19 with a new one.

Figure 2 and Figure 3 depict another embodiment according to the present invention. In particular, Figure 2 shows a schematic illustration of a mail sack filling system and Figure 3 shows a top view Vl and a side view V2 of the mail sack filling apparatus of Figure 2. In this latter embodiment shown in Figures 2 and 3, the receiving opening 31 of the intermediate guide device 13 has a length L31 greater than the length L of the mail sack mouth which surrounds the output opening 32 of the intermediate guide device 13. Moreover, the intermediate guide device 13 is additionally provided with aiding means 21, as illustrated with the shaded element of Figure 2. The aiding means 21 may be a ramp, a slide, an inclined surface or any element facilitating the flowing of the mail items 14 towards the mail sack 19 with a predetermined orientation. The axis of the aiding means 21 is inclined with respective to the horizontal line with a relatively small horizontal angle θ. For example, the angle θ that the inclined surface 21 forms with respect to an horizontal surface may, preferably, be comprised between about 5 degrees and about 15 degrees.

The material of the inclined surface 21 may preferably be a smooth and low friction one to facilitate the flow of the mail items 14 into the mail sack 19. However, in case the surface material is non smooth, the flowing of the mail items 14 towards the receiving opening 31 is in general guaranteed by the relative high speed by which the mail items 14 are ejected from the conveyor belt 11 and conveyed by convey means 12. Moreover, in case a mail item 14 is stuck on top of the aiding means surface 21, the arrival of the next mail item 14 likely pushes the blocked mail item 14 towards the output opening 32 into the sack 19.

In operations, the mail items 14 sorted by the sorting means 11 are ejected towards the conveying means 12, and, in turn, they descend, through the receiving opening 31, towards the intermediate guide device 13. When the sorted mail items 14 reach the intermediate guide device 13, they are guided, by the aiding means 21, towards the output opening 32 so that their falling into the mail sack 19 is controlled and maintained with a predetermined orientation of their planes, more horizontal than the one of state of the art mail sack filling. In fact, in state of the art sack filling, oversized mail items 14 would have a more vertically inclined orientation of their planes since the inclination angle is solely determined by the steepness of descent of the conveying means 12. Advantageously, the inclined surface 21 facilitates an efficient and orderly filling of the mail sack 19. This result is particularly convenient for mail items 14 whose length is greater than the length L of the mouth of the sack 19 since, in known mail sacking methods, such mail items 14 are more at risk of falling with a vertical plan trajectory into the mail sack 19. The vertical falling trajectory of the mail items 14 of state-of-the-art methods decreases the sack capacity filling since the mail items 14 remain in a more vertical orientation that disrupts orderly sack filling. In general, the almost vertical falling of mail items 14 of state of the art methods is due to the angle the conveying means 12 are forming with the horizontal axis which is typically greater than the inclined surface angle θ shown in Figure 3. In Figure 2, two arrows represent the descent trajectory of the planes of the mail items 14 along the conveying means 12 and within the mail sack 19 respectively.

It is contemplated that the mail items 14 may be of various sizes including the standard mail sizes such as, for example, A3, A4, A5 letter and similar ones. In accordance, the intermediate guide device 13 is dimensioned in a way that is capable to canalize the largest of the mail items 14, by preferably being several centimeters wider than the largest mail item 14.

In further embodiments according to the present invention, the output opening 32 of the intermediate guide device 13 of Figures 2 and 3 may also include trap doors 15a, 15b. The embodiments of the present inventions may also be used for any items sorted to sacks such as in pick and place order filling.

It is apparent that there has been disclosed a method, a system and an apparatus for stabilizing mail items in a mail sack 19 that fully satisfy the objects, means, and advantages set forth hereinbefore. For example, the embodiments allow an improving of the filling capacity of mail sacks 19 when filled with mail items 14 while generally maintaining their order. Advantageously, the overall logistics costs are reduced.

List of reference signs

11 sortation means, conveyor belt

12 conveying means, chute, slide, channel

13 intermediate guiding device, frame, tray, receptacle

14 mail items 15a, 15b trap doors 16, 17, 18 lateral sides

19 mail sack, mail bag

21 aiding means, ramp, slide, inclined surface

31 receiving opening at the top side of the intermediate guide device

32 output opening at the bottom side of the intermediate guide device θ angle between the aiding means and an horizontal plane

L length of the sack mouth

L31 length of the receiving opening

Vl top view

V2 side view

Claims

1. A method for aiding a filling of a mail sack (19) with mail items (14), comprising the steps of:

- causing the mail items (14) to fall into a receiving opening (31) of an intermediate guide device (13); and

- within the intermediate guide device (13), influencing the trajectory of the falling mail items (14) to obtain a predetermined orientation of the plane of the mail items (14) during their descent from an output opening (32) of the intermediate guide device (13) towards the mail sack (19) positioned below said output opening (32).

2. A system having means for performing the steps of the method according to claim 1.

3. An apparatus for aiding a filling of a mail sack (19) with mail items (14), comprising:

- an intermediate guide device (13) configured to receive ejected mail items (14) conveyed by conveying means (12) into a receiving opening (31) of an intermediate guide device (13); said intermediate guide device (13) comprising means for influencing the falling trajectory of the mail items (14) to obtain a predetermined orientation of the plane of the mail items (14) during their descent from an output opening (32) of said intermediate guide device (13) towards the mail sack (19) positioned below said output opening (32).

4. The invention according to any of the preceding claims, wherein the intermediate guide device (13) comprises at least three lateral sides (16, 17, 18), beside the receiving opening (31) at its top side and the output opening (32) at its bottom side.

5. The invention according to any of the preceding claims, wherein the opening of the mail sack (19) is arranged along the output opening (32) of the intermediate guide device (13).

6. The invention according to any of the preceding claims wherein the output opening (32) comprises trap doors (15a, 15b).

7. The invention according to any of the preceding claims, wherein means for influencing the falling trajectory of the mail items (14) comprise an inclined surface (21) whose axis is inclined with respect of an horizontal line to control the flow of mail items (14) towards the mail sack (19) via the output opening (32) of the intermediate guide device (13).

8. The invention according to any of the preceding claims, wherein the receiving opening (31) of the intermediate guide device (13) has a length (L31) greater the length (L) of the opening of the mail sack (19).