Stacking machine for processing standard- up to C4-sized postal items

Abstract

 A stacking machine comprising a launching device (3) to handle standard and elongated postal items (40) one by one, a bottom wall (18) to support a longitudinal side of the postal item when the latter is processed by the launching device (3), a stop wall (9) facing the launching device (3) to stop the postal items launched by the launching device (3), a compacting module (6) comprising a resting plane (15) to support a longitudinal side of the stacked postal items (40) processed by said launching device (3), and a first helix (10) arranged to engage a tail portion (42) of a postal item (40) exiting the launching device (3) and configured to guide the tail portion (42) towards the compacting module (6) and to free the outlet of the launching device (3), the stop wall (9) being spaced from the launching device (3) so that when a C4 postal item contacts the stop wall (9), the first helix (10) engages the tail portion of the C4 postal item.

Description

[0001] The present invention relates to an improved stacking machine for postal sorting machines for processing both standard-sized items (letters up to C5) and of larger or extended sizes (objects up to the known C4 or slightly higher).

[0002] The postal items are processed by machines designed to individualize, and sorting postal items.

[0003] In the field of machines for the processing of postal items and in particular of standard letters which are typically also sequenced, increasing mechanization and automation for processing ever-larger size formats is a constantly felt need. However, processing objects up to C4, including open magazines and objects covered with cellophane (poliwrapped), and particularly to achieve a proper stacking, increases the risk of jamming due in particular to interference between the tail portion of a postal item and the head portion of the next postal item during the step of generating the stack of postal items particularly due to dynamic friction between the incoming object and the stacked object. Jams may also cause, in addition to machinery arrests, damage to the postal item which is then delivered to its final destination in poor condition or may not even be deliverable.

[0004] The aim of the present invention is to provide a stacking machine with innovative technical solutions capable of increasing the number of formats that can be automatically processed up to C4 format(including items such as paper bags, open magazines and poly-wrapped articles), including if necessary the speed reduction of the machine, but without increasing machinery jamming and damage rate of the postal items.

[0005] The aim of the present invention is achieved by way of a stacking machine made according to claim 1.

[0006] For a better understanding of the present invention a preferred embodiment is now described, purely by way of example without limitation, with reference to the accompanying drawings in which:

• Figure 1 is a perspective view of a stacking machine according to the present invention;
• Figure 2 is a front view along a stacking direction of figure 1;
• Figure 3 is a schematic view of a component of figure 1;
• Figure 4 is a schematic view of the process of stacking run by the stacking machine of the present invention, and
• Figure 5 is a schematic view of a detail of the stacking machine of Figure 1 in two working positions.

[0007] In Figure 1 is illustrated with 1, as a whole, a stacking machine for postal items. The stacking machine 1 can be arranged in series, such as downstream of a sorting machine comprising a plurality of channels 2, each corresponding to a set of postal addresses grouped according to the sorting needs (e.g. all postal items destined to one or more Postal Code ZIP or zip codes) and/or sequencing (e.g. addresses with consecutive delivery points destined to one or more postal carriers). Inside the channel 2 postal items are individually transported by the transport system of the machine and spaced at a distance usually referred to as 'Gap' (distance between the tail of an object and the head of the next object); the stacking machine 1 operates to arrange the postal items in special stacks aligned along two substantially orthogonal planes and having in common a line substantially perpendicular to each postal item.

[0008] The stacking machine includes a launching device 3 to impart speed (momentum) to the postal items spaced from each other and coming from channel 2 and a compacting group 6 which receives individualized postal items launched to form a stack (or pack) of postal items in a controlled manner. In particular, the postal items come in contact by inertia to a stop device 4 to block each postal item along a trajectory (schematically shown in figure 4a) substantially straight, at least partially defined by the launching device 3 and by a guide group 5 to guide the postal item along the launch trajectory towards the compacting group 6. In particular, the launching device 3 is made of rollers that pick up a head portion of the postal item to push it towards the stop device 4. In particular, the launching device 3 comprises a profiled roller 7 and a counter roller 8 rotating around respective axes parallel to each other. The stop device 4 comprises a transverse wall 9 to the launch trajectory of the postal item determined in combination by the launching device 3 and the guide group 5 to stop the head portion of the postal item against a stop defined by the wall 9.

[0009] The guide group 5 controls the position of the postal item to ensure the correct positioning towards the wall 9 with respect to the compacting group 6 and to avoid trajectories that would cause jamming. In particular, the guide group 5 preferably includes a pair of helixes 10, 11 having respective axes transverse to the trajectory of the postal item towards the wall 9, the helix 10 being longer than helix 11 and respective axes being spaced at a distance at least twice the diameter of the helix 10. In this way, the helix 11 engages the tail portion of the standard format postal item as detailed below. The helix 10 is proximal to the roller 7 and the helix 11 is proximal to the wall 9 and each has respective threads 12, 13 as to contact at least one edge of the postal item interposed between the head portion and a tail portion while the postal item moves towards the wall 9. Threads 12, 13 and the relative rotation direction of the helixes 10, 11 are such that when a postal item is launched by the launching group 3, the postal item itself is translated substantially perpendicular to the launch trajectory towards the compacting group 6. In particular, the helix 10 is disposed in the half adjacent to the roller 7 of the distance between the roller itself and the wall 9 so as to cooperate with a tail portion of a postal item which has an elongated shape, such as a C4, when the latter contacts the wall 9.

[0010] Moreover, the threads of the helix 10 have a radius, possibly variable, and a beginning in the axial direction so that a front portion of the postal item leaving the launching device 3 does not interfere with the same threads of the helix 10.

[0011] In addition, the guide group 5 comprises a diverter 14 to intercept the tail portion of the newly launched postal item, thereby permitting a head portion of the next postal item processed by the launching device 3 to overlap without interfering with the tail portion of the postal item already launched. Then the trajectory of the front portion of each postal item is not conditioned by the helix 10 while normally only the tail portion of the elongated postal items (C4) is translated in the direction of the compacting group 6 via the helix 10.

[0012] Preferably, the diverter 14 comprises one or more elastically flexible blades placed immediately downstream of the launching roller 7. A blade 14 cooperates with the postal items having a large size, such as C4, while another blade 14, of lesser stiffness, cooperates with standard format letters. In addition, the blades 14 are positioned in order to urge a tail portion of the postal item to engage the helix 10 having little or no effect on the engaging manner of the head portion on the helix 11.

[0013] When the postal item contacts the wall 9, the relative tail portion is translated by the helix 11 when the item presents a standard format. If the postal item presents a larger length (i.e. C4), the relative tail portion is translated by the helix 10 towards the compacting group 6. The compacting group 6 comprises a resting plane 15 for the longitudinal side of the postal items, a transport belt device 16 and a compactor 17 substantially perpendicular to the resting plane 15 and adapted for supporting the pack of postal items. In particular, the resting plane 15 is tilted downwardly, i.e. of 10°, on the opposite side to the channel 2 plane so that a very large sized postal item but with a low stiffness will lean due to gravity upon the previous postal item or directly on the compactor 17 therefore avoiding that the postal item itself would accidentally bend towards the channel 2. Moreover, again in order to avoid disturbing the launching trajectory of the postal items leaving the launching device 3, the resting plane 15 has a vertical dimension less than that from which the postal items are launched. In particular, the launching height is determined by a transverse back wall 18, preferably perpendicular to the roller 7 and to the counter roller 8 defining an opening from which protrudes the thread 12 of the helix 10. The back wall 18 defines a support for the longitudinal sides of all postal items from channel 2. For example, the resting plane 15 and the back wall 18 are separated by a step 19 so that a postal item with a low stiffness would fall by gravity on the resting plane 15 without folding back towards the launch trajectory.

[0014] The step 19 is interposed between the compacting group 6 and the helixes 10, 11 for preventing prolonged contact time between the helixes 10, 11 and the back face of the last stacked postal item, thus avoiding abrasion upon the object itself due to the continuous dragging of the helix in rotation.

[0015] When the postal item comes in contact with the resting plane 15, it is also supported by the transport device 16 including a first belt 20 proximal to the wall 9 and a second belt 21 proximal to the helix 10 and spaced from the first belt 20. The belts 20, 21 and compactor 17 are conducted by a motorized system M preferably synchronously, so that straight movements are equal and simultaneous. The motorized system M is controlled by a control unit C which is programmed to move the compactor 17 and belts 20, 21 on the basis of one or more characteristic parameters of the geometry and/or type of postal item to be stacked detected by a series of sensors indicated schematically with S.

[0016] According to a preferred embodiment of the present invention, the characteristic parameters comprise the thickness, format (height and length) and the outer surface of the type of processed postal items. For example, when the postal item is a standard letter (e.g. envelope C5), the control unit C controls a first movement which consists in distancing the compactor 17 with respect to the roller 7 and the helixes 10, 11 and in particular consequently moving the belts 20, 21 by an amount proportional to the thickness detected upstream of the sensor S. When the postal item has a high friction coefficient, for example, is wrapped in a polymeric material (poliwrapped), the control unit C controls a second movement which provides a removal of a quantity greater than the previous case, in equality of thickness measured. When the next item should present a reduced thickness compared to the space already available, the control unit C controls the approach of the compactor 17 to helixes 10, 11 or the maintainance of the position if the distance is not excessive.

[0017] Preferably, the compactor 17 comprises an arm 22 projecting transversely from the resting plane 15 and a wall 23 hinged at a free end portion 24 to the arm 22 and rigidly connectable to the belt 20. In particular, the belt 20 has a plurality of slots 25 and the wall 23 has a projection 26 adapted for engagement within a groove 25. The hinge axis between the wall 23 and the arm 22 is parallel to the advancing direction of the belts 20, 21 so that the projection 26 engages a slot 25 following an arc of a circle trajectory and the slots 25 have a length so as not to interfere with said trajectory.

[0018] In Figure 3 is illustrated in greater detail a preferred embodiment of the roller 7. In particular, the roller 7 has a profile defining a plurality of sections having different diameters to curve or bend the postal item profile thus giving greater stiffness to the latter during the launch step. In particular, the roller 7 has a first and a second tapered portion 27, 28 converging towards a central body 29 interposed between the tapered portions. The roller 7 further comprises a cylindrical section (slightly convex) where a strap 30 is wound and a deformable ring 31 both mounted on the central body 29, the strap 30 being interposed between the deformable ring 31 and the tapered portion 27 proximal to the bottom wall 18. Preferably, the deformable ring 31 has a diameter greater than the one determined by the sum of the diameter of the main body 29 and twice the thickness of the strap 30 and is made of a material having a high elastic deformability. Moreover, this material has a deformation load such that the deformable ring 31 substantially presents the maximum diameter when on the roller 7 transit non rigid postal items, such as a very thin standard letter with an envelope made of low weight density paper and an insert consisting of a thin sheet. According to one aspect of the present invention, when the roller 7 processes postal items having a size and a stiffness greater than those of a normal letter, the deformable ring 31 is such to deform and therefore does not significantly contribute to the deformation of rigid postal items. A large rigid postal item presents in fact a sufficient dimension to cooperate with the tapered portion 28 and be deformed by the latter. In order to drive differently sized postal items as well as possible, the counter roll 8 includes a deformable counter ring 32 contacting the strap 30 and a deformable counter ring 33 contacting the central body 29 between the deformable ring 31 and the tapered portion 28. As illustrated in Figure 3b the counter ring 33 maintains the postal item near the central body 29, so that the tapered portion 28 can bend the item itself in the intended way.

[0019] The operation of the stacking machine 1 is as follows (Figure 4).

[0020] When the launching device 3 does not process any postal item the fins 14 are in a non deformed position that interferes with the trajectory set by the launching device 3. For example they are inclined by the roller 7 towards the wall 9. Furthermore, as shown by arrows, both the fins 14 and the helixes 10, 11 guide the processed postal item in a direction transverse to the launching trajectory in order to free the launching area for the next postal item avoiding or at least reducing interference and jams.

[0021] In Figure 4b, a postal item 40 of C4 format is processed by the roller 7 and by the counter roll 8 and is consequentially stiffened by the curvature illustrated in Figure 3a. Given this stiffness and the restraint formed by the rollers 7, 8, the fins, or better the blade 14 proximal to the bottom wall 18, have such a stiffness as to be deformed and a head portion 41 of the postal item 40 is directed towards the wall 9 and is engaged in the helix 11. When the postal item 40 no longer contacts rollers 7, 8, the action of the blade 14 is applied to a tail portion 42 of the postal item 40 to engage the tail portion of the helix 10 itself and to free the trajectory defined by the rollers 7, 8 allowing the advancement of the subsequent postal item 50 (Figure 4c). In particular, according to the present invention, the action of the blade 14 is assisted by the helix 10 so as to free as quickly as possible the trajectory of the launching device 3 and to avoid interference between a head portion 51 of the postal item 50 and the tail portion 42. In addition, the blade 14 applies such an action that the blade 14 is deformed when any curved postal item is still in contact with the rollers 7, 8 and at the same time, for moving the tail portion of the heavier postal items considering however, that when the blade 14 acts by bringing the tail portion 42 of C4 items near to helix 10, postal items are like free, released bodies except for the restraint by the friction force.

[0022] While the postal item 50 longitudinally advances stiffened by the curvature obtained by the tapered portions 27, 28, the helix 10 completes the guiding action by leading the tail portion 42 towards the wall 23.

[0023] Moreover, as already previously mentioned, the motorized system M is controlled so as to adjust the position of the stack or pack of postal items according to thickness and/or other physical postal item characteristics (e.g. height and/or length and/or presence of non-wrapped magazines and/or postal items packed in an envelope of polymeric material, i.e. nylon) measured by appropriate sensors S. For example, the postal item 40 has a thickness such that the control unit C controls the retraction of a portion of the wall 23 at a dimension S1. Whereas, the postal item 50 has a thickness S2 and, correspondingly, the control unit controls a displacement S2 of the wall 23. In addition, the sensors S may comprise a sensor to detect the presence of metal staples in a magazine, for example an inductive sensor. For example, said sensor S is placed on the bottom wall of the channel 2 on which the backs of the magazines bound by metal staples rest.

[0024] The advantages of the stacking machine 1 described and illustrated herein are as follows.

[0025] The helix 10 allows the guiding of the tail portion of elongated format postal items after the latter has been processed by the launching device 3, i.e. is no longer in contact with the rollers 7, 8 to free the launch trajectory allowing closer spacing between postal items having different sizes. This method prevents non rigid postal items from bending and interfering with the movement trajectory of the postal items imposed by the launching device 3 and, therefore, avoiding jams. In addition, by way of the helix 10 it is possible to process postal items with formats up to C4. To achieve this aim, the wall 9 is spaced from the roller 7 of the launching device 3 so that when a head portion of a C4 format postal item contacts the wall 9, the relative tail portion is engaged in the helix 10 and has already been spaced from the roller 7, 8. It has been verified that by spacing the wall 9 from the launching device, the postal items of a size less than C4 effectively free the trajectory even without interacting with the helix 10.

[0026] To achieve the same purpose, the resting plane 15 is inclined and vertically spaced from the back wall 18.

[0027] The helix 10 is longer than the helix 11 for engaging as quickly as possible the tail portion 42 of the postal item 40 and thus freeing the trajectory for the next postal item 50 so as to minimize the delay between two successive postal items. The blades 14 are provided for the same purpose.

[0028] By way of the deformable ring 31 the stacking machine 1 can easily process postal items having different formats.

[0029] The belts 20, 21 and the wall 23 are motorized for implementing control methods that promote the correct positioning of the postal items in a stacked position. For example, when the control unit C controls varying movements for postal items having thickness, format and/or different types of outer surfaces (paper envelope, open magazine, poliwrapped), the controller is programmed to control a movement of belts 20, 21 and wall 23 based on an offset value table optimized to facilitate the stacking of the individual postal item. In this way it is possible for example to create more space on the resting plane 15 for the arrival of the postal item 50 having a high-friction surface (poliwrapped) and successively reassemble the pack to prevent the bending over of postal items.

[0030] Finally, it appears clear that the stacking machine 1 here described and illustrated can be modified or changed without thereby going beyond the scope of protection as defined by the appended claims.

[0031] Some applications may only include the helix 10 which engages the tail portion 42 of an elongated postal item. In fact, shorter postal formats, such as letter format, present a low inertia and are moved to the compacting group 6 by impact against the wall 9 and/or by gravity and without substantially cooperating with the helix 10. Assistance for directing the letter format postal item to the compacting unit 6 may come from the diverter 14, which pushes the tail portion of each postal item to the compacting group 6 when the item is no longer engaged on the rollers 7, 8.

[0032] One of the two tapered portions 27, 28, in particular, the tapered portion 28, may be absent, the curvature being defined however by the action of the remaining tapered portion and of the deformable roller 31. In addition, the counter roller 8 may be absent and the pressure to keep the postal item against the roller 7 to obtain the curvature is applied by a conveying strap 60 which defines the channel 2 and cooperates with one of the faces of the postal item. The conveying strap 60 can be interposed between the roller 7 and a plate which has a distance from the roller 7 defining a contact surface for the postal item and therefore defining a curved wave shape. Moreover, according to an alternative, it is possible to mount the wall 9 in a mobile manner and couple the wall itself to a dampener so that an incoming postal item from the launching device 3 impacts against the wall 9 and activates the dampener dissipating at least part of the kinetic energy. Preferably, the wall 9 is hinged around an axis A and a dampener 60 is coupled in parallel with a biasing spring 61. In particular, the spring 61 is compressed during an impact and takes the wall 9 back to an initial position advanced towards the launching device 3. Advantageously, the dampener 60 and the spring 51 are connected to the wall 9 by means of a leverage 70, i.e. by a mechanism that amplifies or reduces the movement of the wall 9 due to an impact with a postal item 40. In addition to the dampener 60, the wall 9 may also present a layer 62 preferably extended on the wall itself and made out of a soft material to further absorb the impact energy.

[0033] For example (Figure 5), the leverage 70 is double-L-shaped rotating around a hinge 71. Particularly, when a head portion of the postal item 40 launched from the rollers 7 and 8 collides with the soft layer 72 on the wall 9, the leverage 70 begins to rotate about the hinge A and compresses both the spring 61 and the viscous hydraulic actuator 60.

Claims

1. A stacking machine comprising a launching device (3) to handle standard and elongated postal items one by one, a bottom wall (18) to support a longitudinal side of the postal item when the latter is processed by said launching device (3), a stop wall (9) facing said launching device (3) to stop the postal items launched by said launching device (3), and a compacting module (6) comprising a resting plane (15) to support a longitudinal side of the stacked postal items (40) processed by said launching device (3), characterised by comprising a first helix (10) arranged to engage a tail portion (42) of a postal item (40) exiting the launching device (3) and configured to guide said tail portion (42) towards said compacting module (6) and to free the outlet of said launching device (3), said stop wall (9) being spaced from said launching device (3) so that when a C4 postal item comes into contact with said stop wall (9), said first helix (10) engages the tail portion of said C4 postal item.

2. The stacking machine according to claim 1, characterised in that said first helix (10) at least partially projects with respect to said bottom wall (18) and has a radius and a position such as not to substantially deviate the trajectory of a head portion (41) of said postal item.

3. The stacking machine according to any of the preceding claims, characterised by comprising at least one elastic element (14) configured to cooperate with the tail portion (42) of the postal item (40) so as to promote the coupling between the latter and said first helix (10) after said postal item (40) has been processed by said launching device (3).

4. The stacking machine according to any of the preceding claims, characterised in that said launching device (3) comprises at least one profiled roller (7) to curve the postal item (40) so as to obtain a longitudinal stiffening of the latter while said postal item (40) is processed by said launching device (3).

5. The stacking machine according to claim 4, characterised by comprising a deformable ring (31) mounted on said roller (7) and made of a material such as to curve a non rigid postal item (40) and be deformed by a rigid postal item (50).

6. The stacking machine according to claim 5, characterised in that said roller comprises at least one tapered end portion (27) and in that said deformable ring (31) is spaced from said tapered end portion (27).

7. The stacking machine according to claim 6, characterised in that at least one elastic element (14) is arranged downstream of said profiled roller (7) to cooperate with said postal item (40) and is proximal to said launching device (3).

8. The stacking machine according to any of the preceding claims, characterised by comprising a second helix (11), said first helix (10) being interposed between said second helix (11) and said launching device (3) and being spaced from said first helix (10) so as to engage a tail portion of a standard postal item arranged in contact with said stop wall (9).

9. The stacking machine according o any of the preceding claims, characterised in that said resting plane (15) is inclined downwards.

10. The stacking machine according to any of the preceding claims, characterised in that said resting plane (15) is separated from said bottom wall (18) by a step (19).

11. The stacking machine according to any of the preceding claims, characterised in that said compacting module (6) comprises at least one motorised mobile member (17, 20, 21) and by comprising an electronic control unit (C) to control said mobile member (17, 20, 21).

12. The stacking machine according to any of the preceding claims, characterised in that said wall (9) is mobile and by comprising a dampener (60) and/or spring (61) coupled with said wall to dissipate the striking energy of a postal item against said wall (9).

13. The stacking machine according to claim 12, characterised in that said dampener (60) and/or said spring (61) are connected to said wall (9) by means of a leverage.

14. A control method for a stacking machine according to claim 11, characterised by comprising the step of detecting one or more typical size parameters and/or parameters of the outer surface of each postal item processed by means of a plurality of sensors and the step of controlling said mobile member (17, 20, 21) on the basis of said parameters.

15. The method according to claim 14, characterised by comprising the step of moving said mobile member (17, 20, 21) away from said first and second helixes (10, 11) by a first amount (S1) and the step of approaching said mobile member (17, 20, 21) to said first and second helixes (10, 11) by a second amount (S2) other than said first amount (S1).

16. The method according to claim 15 for a stacking machine according to claim 10 and 11, characterised in that said first amount (S1) is such as to bring the pack of postal items downstream of said step (19) so as to avoid contact between the back portion (face) of the postal item and at least said first helix (10).

Drawing