Patent Description:
Automatic postal sorting machines are well known in the patent literature. Postal sorting machines load a number of postal items and then output the postal items in a delivery order so that the mailman/mailwoman has a stack of mail in the correct order for deliveries. This saves a lot of time during the delivery.

These machines can be very large, very complex and very expensive. For smaller post offices, such machines are a very large expense and such machines are typically not purchased. The post is therefore sorted by hand which is a tiring and slow operation.

Automatic postal sorting machines can typically be divided into two separate types. A first type of machine is a multiple pass sorting machine where the post is sorted in multiple passes similar to a linked list in a software program. This requires a fast machine as it would otherwise take a long time to complete the sorting operation.

Another type of machine is known as a single pass machine. The machine reads in the postal items in a first operation and stores the individual post items in individual bins and remembers which bins have which postal items. Once all the postal items have been loaded into the individual bins, the machine ejects the postal items from the bins in the correct order. This type of machine requires a number of bins which is equal to the number of unique addresses on the postal items in the sorting operation. If there are <NUM> different postal addresses, <NUM> bins are needed. These types of machines are typically slower machines as the machine has to move the postal items into individual bins and then eject the post from the bins in a specific order. One example of such an automatic single pass postal sorting machine is described in <CIT>.

A first aspect of the current invention is to provide an automatic postal sorting machine which is faster than the prior art machines.

A second aspect of the current invention is to provide an automatic postal sorting machine which is more robust than the prior art machines.

These aspects are provided at least in part by a sorting machine according to claim <NUM>. According to claim <NUM>, the sorting machine automatically sorts a plurality of postal items and includes a plurality of sorting modules. Each sorting module includes an elevator assembly and an input conveyor. The elevator assembly has an elevator frame, an elevator cabin movably supported by the elevator frame, a plurality of trays arranged as a vertical stack of trays inside the elevator cabin, and an elevator mechanism arranged to move the elevator cabin up and down in a vertical direction relative to the elevator frame. Also, each tray is adapted to be displaced with respect to the elevator cabin between a first position and a second position, the first position being inside the elevator cabin and the second position being at least partially outside the elevator cabin in a horizontal direction. Further, the input conveyor is arranged at a fixed vertical position with respect to the elevator assembly. The elevator mechanism is arranged to selectively bring at least one tray into a vertical alignment with said input conveyor to facilitate a transport of a postal item disposed on the input conveyor to the tray which is in vertical alignment with the input conveyor. Moreover, the sorting machine is arranged to transfer a postal item from the input conveyor to the vertically aligned tray by first moving said tray outside the elevator cabin to the second position where the tray is disposed, at least partly, beneath an upper surface of the input conveyor, and subsequently simultaneously operating the input conveyor and displacing the tray in a direction of movement of the input conveyor to the first position such that a postal item leaves the input conveyor and is deposited on the tray while the postal item is travelling in the same direction as the tray.

In this way, a more secure transfer of the postal item to the tray is achieved. This allows the entire machine to operate faster while still having a stable delivery of the postal items.

In one embodiment, the sorting module includes a flap member disposed outside the elevator cabin and adapted to be displaced between an engaged position and a free position. In the engaged position, the flap member is adapted to be located behind a postal item disposed inside the tray, when the tray is arranged at the second position to facilitate a removal of the postal item from the tray. In the free position, the flap member is disposed away from the tray.

In one embodiment, to remove a postal item from the tray, the tray is moved to the second position, the flap member is displaced to the engaged position to arrange the flap member behind the postal item stored inside the tray, and the tray is pushed back to the first position. Further, an engagement of the flap member with the postal item facilitates the removal of the postal item from the tray when tray is pushed to the first position. In this way, the flap member itself does not have to be displaced in a large horizontal distance. This again optimizes the speed of the machine and reduces the need for many different actuators.

In one embodiment, the flap member includes a plurality of flaps and the tray includes a rear wall comprising a plurality of openings to facilitate an insertion of the plurality of flaps inside the tray when the flap member is arranged in the engaged position.

According to one embodiment, the plurality of flaps engages with the postal item stored inside the tray when the tray is moved from the second position to the first position to remove the postal item from the tray.

Further, in one embodiment, each sorting module includes an output conveyor to receive a postal item removed from the tray. The output conveyor is adapted to hold a first postal item in a first buffer position and a second postal item in a second buffer position.

In one embodiment, the output conveyor includes a first portion and a second portion extending outwardly from the first portion and arranged at an inclination relative to the first portion. In the first buffer position, a postal item is disposed on the first portion, and in the second buffer position, a postal item is disposed on the second portion. In one embodiment, the angle between the first and second portions is greater than <NUM> degrees, greater than <NUM> degrees or greater than <NUM> degrees. By arranging the first and second portions at an angle to each other, the second portion can be arranged lower than the first portion. In this way, the second portion of the output conveyor of one sorting module can be located underneath a first portion of an output conveyor of an adjacent sorting module. In this way, the sorting modules can be arranged closer together thereby reducing the size of the complete sorting machine.

In one embodiment, each sorting module includes a linear actuator adapted to pull the tray out of the elevator cabin and push the tray back into the elevator cabin and thereby move the tray between the first position and the second position.

According to one embodiment, each tray includes an engagement structure defining a recess, and the linear actuator includes a hook member adapted to engage with the engagement structure to pull the tray out of the elevator cabin. The hook member and the recesses in the trays are arranged such that the hook member passes through the recesses of the trays as the trays are moved in the vertical direction. In this way, the hook member can be located at a stationary position while the trays move up and down. When a tray is stopped in the correct position, the hook member is already engaged with the recess and the hook member can then be pulled out by the linear actuator to pull the tray out. A separate "hook engaging" motion and actuator is not required.

According to one embodiment, the sorting machine further includes a transport conveyor having a plurality of transport belts, one transport belt associated with each sorting module. The plurality of transport belts are adapted to pivot between a horizontal position and a pivot position. The transport belts are arranged in-line when located at the horizontal position. Moreover, each of the transport belts is moveable to a pivot position to transport a postal item from the transport conveyor to a sorting module associated with the transport belt.

Referring to <FIG>, an exemplary sorting machine <NUM> suitable for automatically sorting a plurality of postal items <NUM> is shown. In this embodiment, the sorting machine <NUM> comprises six essentially identical sorting modules <NUM>, but other embodiments could be provided with more or less sorting modules. The sorting machine <NUM> includes a plurality of sorting modules <NUM> arranged linearly in a row, a transport conveyor <NUM> extending substantially parallel and along the length of the row of sorting modules, a loading conveyor <NUM> for delivering the plurality of postal items <NUM> to the transport conveyor <NUM>, and an input station <NUM> for loading the postal items <NUM> on the loading conveyor <NUM>. In an embodiment, the input station <NUM> may include a robotic gripper (not shown) adapted to pick postal items <NUM> one by one from an input stack of postal items and position the postal items <NUM> one by one on the loading conveyor <NUM>. Alternatively, an operator may manually placed the postal items <NUM>, one by one, on the loading conveyor <NUM>.

The sorting machine <NUM> may further include a scanner <NUM> to scan an upper surface of each postal item <NUM> disposed on the loading conveyor <NUM> to identify/determine an address to which the postal item <NUM> is to be delivered. In an embodiment, the scanner <NUM>, such as, a camera, is adapted to take a photograph of the upper surface of the postal item <NUM> and then analyse the photograph to determine the correct address via a computer vision system. In an embodiment, the scanner <NUM> may use standard text recognition systems to extract correct address associated with the postal item <NUM>. In some cases, the scanner <NUM> may not be able to recognize the address written on the postal item <NUM>. In such a case, the postal item <NUM> continues into the machine and is stored in a bin as will be described later in this specification. The image taken by the camera is then shown to a human operator. The human operator can read the address and type in the correct address. The correct address is then assigned to the postal item <NUM> stored in the machine for proper sorting.

The loading conveyor <NUM> is adapted to move/convey each postal item <NUM> to the transport conveyor <NUM>. The transport conveyor <NUM> extends along a width of all the sorting modules <NUM> of the sorting machine <NUM>, and is adapted to deliver the postal items to any one of the sorting modules <NUM>. To facilitate a delivery of postal items <NUM> to each of the sorting modules <NUM>, the transport conveyor <NUM> may include a plurality of individual transport belts <NUM> arranged between a first longitudinal end <NUM> and a second longitudinal end <NUM> of the transport conveyor <NUM>. Each transport belt <NUM> includes a frame <NUM> (best shown in <FIG> and <FIG>) and a belt <NUM> (best shown in <FIG> and <FIG>) supported by the frame <NUM> and adapted to move relative to the frame <NUM>. It may be appreciated that each transport belt <NUM> is associated with a single sorting module <NUM> and facilitates the delivery of the postal items <NUM> to the associated sorting module <NUM>. Moreover, each transport belt <NUM> is adapted to move/pivot between a horizontal position (shown in <FIG>) and a pivot (i.e. inclined) position (shown in <FIG>). In the horizontal position, the transport belts <NUM> facilitates a transfer/conveyance/transport of the postal items <NUM> to a next/adjacent/neighbouring transport belt <NUM>, while in the pivot position the transport belts <NUM> enables a delivery of the postal items <NUM> to the associated sorting modules <NUM>.

As shown in <FIG> and <FIG>, when the transport belts <NUM> are in the horizontal position, the transport belts <NUM> are aligned and coplanar with each other and extend substantially in a direction of movement of the transport conveyor <NUM>, i.e., in a direction 'A'. Further, each of the transport belts <NUM>, when arranged/disposed in the pivot position, is located at an inclination relative to the direction of movement of the transport conveyor <NUM> and defines an opening <NUM> (shown in <FIG>) through which the postal items <NUM> fall onto the associated sorting module <NUM>. In an embodiment, a controller may control a movement of the transport belts <NUM> to the horizontal position and to the pivot position to enable a transport of the postal items <NUM> to the desired sorting modules <NUM> to facilitate a correct sorting of the postal items <NUM>. As shown in <FIG> the transport belt <NUM> may be supported on the associated sorting module <NUM>, and may be supported by a bracket <NUM> extending substantially perpendicularly from an elevator frame <NUM>. The transport belt <NUM> may be pivotally coupled to the bracket <NUM> and may pivot about a pivot axis <NUM> to move between the horizontal position and the pivot position. In this embodiment, the pivot axis is located at the downstream side of the sorting module, so that when the transport belt is pivoted to the pivot position, the opening is arranged at the upstream side of the sorting module.

Referring to <FIG>, a single sorting module <NUM> is shown. It should be noted that the sorting module <NUM> of <FIG> has an output conveyor <NUM> which is mirrored with respect to the sorting modules <NUM> shown in <FIG>, but is otherwise identical in function. It may be appreciated that a construction, a structure, and a function of each of the sorting modules is identical, therefore the construction, the structure, and the function is explained with reference to a single sorting module <NUM>. As shown in <FIG>, the sorting module <NUM> includes an input conveyor <NUM> (best shown in <FIG>) disposed beneath the associated transport belt <NUM> to receive the postal items <NUM> from the transport conveyor <NUM>, an elevator assembly <NUM> adapted to receive the postal items <NUM> from the input conveyor <NUM>, and an output conveyor <NUM> for receiving the postal items <NUM> from the elevator assembly <NUM>.

Referring to <FIG>, the input conveyor <NUM> is adapted to receive the postal items <NUM> from the transport conveyor <NUM> and move in a direction 'B' that is substantially perpendicular to the movement of the transport conveyor <NUM>. As shown, the input conveyor <NUM> is adapted to move the postal items <NUM> towards the elevator assembly <NUM>. The input conveyor <NUM> includes a first longitudinal end <NUM> disposed distally from the elevator frame <NUM>, a second longitudinal end <NUM> disposed proximally to the elevator frame <NUM>, a first portion <NUM> and a second portion <NUM>. The first portion <NUM> and the second portion <NUM> may be separated by a virtual line <NUM> such that the first portion <NUM> may extend from the first longitudinal end <NUM> to the second portion <NUM>, while the second portion <NUM> may extend from the first portion <NUM> to the second longitudinal end <NUM>. It may be appreciated that the first portion <NUM> is arranged/located directly below the associated transport belt <NUM>, while the second portion <NUM> may be located at an offset from the transport belt <NUM>. Further, the input conveyor <NUM> is supported on the bracket <NUM> and the second longitudinal end <NUM> is disposed at a distance from the elevator frame <NUM>, such that a longitudinal gap <NUM> is defined between the input conveyor <NUM> and the elevator frame <NUM>.

In an embodiment, the input conveyor <NUM> is adapted to hold a single postal item <NUM> in two buffer positions 200a, 200b. The postal item <NUM> drops from the transport conveyor <NUM> and rests on the input conveyor <NUM> in a first buffer position 200a. Accordingly, in the first buffer position 200a, the postal item <NUM> is disposed directly beneath the transport belt and on the first portion <NUM>, while in a second buffer position 200b, the postal item <NUM> is arranged on the second portion <NUM> of the input conveyor <NUM>. Accordingly, in the second buffer position 200b, the postal item <NUM> is located proximate to the elevator assembly <NUM> relative to the first buffer position 200a. In this manner, the input conveyor <NUM> is adapted to hold two postal items <NUM> simultaneously. For so doing, in an implementation, a length of the input conveyor <NUM> may be twice a width of the transport belt <NUM>. From the second buffer position 200b, the postal item <NUM> moves/falls into a tray <NUM> of the elevator assembly <NUM> as described in more detail below. In one embodiment, instead of one long input conveyor <NUM>, two separate conveyors may be provided in line with each other.

To optimize the sorting speed of the machine, when a postal item is dropped onto the first portion, the input conveyor will activate and move the postal item to the second portion in order to make the first portion available for a new postal item.

As shown in <FIG>, the elevator assembly <NUM> includes the elevator frame <NUM> extending upwardly from a ground surface, an elevator cabin <NUM> movably supported on the elevator frame <NUM> and adapted to move vertically up and down along a height of the elevator frame <NUM>, a plurality of trays <NUM> arranged/arrayed/stacked vertically within the elevator cabin <NUM>, and an elevator mechanism <NUM>,<NUM> (shown in <FIG>) adapted to move the elevator cabin <NUM> up and down in the vertical direction relative to the elevator frame <NUM>. The elevator mechanism may be a chain or belt <NUM> connected to the elevator cabin <NUM> and adapted to move the elevator cabin <NUM> in the vertical direction. In an embodiment, the elevator mechanism may include an electric motor <NUM> (shown in <FIG>) to operate the chain or the belt <NUM>.

Further, each tray <NUM> is adapted to have a first position (best shown in <FIG> and <FIG>) inside the elevator cabin <NUM> and a second position (best shown in <FIG> and <FIG>) outside the elevator cabin <NUM>. To move the tray <NUM> between the first position and the second position, the tray <NUM> is moved in a horizontal direction substantially parallel to the direction of movement of the input conveyor <NUM>. Outside the elevator cabin <NUM> and in the second position, the tray <NUM> is arranged distally from the elevator cabin <NUM> and at least partly beneath the input conveyor <NUM>.

Referring to <FIG>, to pull the tray <NUM> out of the elevator cabin <NUM> to the second position, and push the tray <NUM> inside the elevator cabin <NUM> to the first position, the sorting module <NUM> may include a tray displacing mechanism <NUM> extending substantially perpendicular to the elevator frame <NUM> and disposed outside the elevator cabin <NUM>. In an embodiment, the tray displacing mechanism <NUM> is supported by the bracket <NUM> and may extend from the elevator cabin <NUM> to the input conveyor <NUM> such that a portion of the tray displacing mechanism <NUM> is located directly beneath/below the input conveyor <NUM>. In an embodiment, the tray displacing mechanism <NUM> includes a pair of rails (best shown in <FIG>), for example, a first rail <NUM> and a second rail <NUM> disposed spaced apart and substantially parallel to the first rail <NUM>, defining a cavity <NUM> (shown in <FIG>) therebetween. Outside the elevator cabin <NUM>, the tray <NUM> is supported on the rails <NUM>, <NUM>, and slides relative to the rails <NUM>, <NUM>.

Further, as shown in <FIG> and <FIG>, the tray displacing mechanism <NUM> may include a linear actuator <NUM> to pull the tray <NUM> out of the elevator cabin <NUM> to the second position and push the tray <NUM> inside the elevator cabin <NUM> to the first position. In an embodiment, the linear actuator <NUM> may include a hook member <NUM> and a drive belt <NUM> connected to the hook member <NUM> and adapted to move the hook member <NUM> in a horizontal direction along a length of one of the rails, for example, the first rail <NUM>. The hook member <NUM> is adapted to engage with the tray <NUM> when the tray is disposed in the first position and aligned with the rails <NUM>, <NUM>, and is adapted to pull the tray <NUM> outside the elevator cabin <NUM>. The hook member <NUM> may include an L shape having a first member <NUM> connected/attached to the belt <NUM> and a second member <NUM> extending substantially perpendicular to the first member and adapted to engage with the tray <NUM> to pull the tray <NUM>, disposed in the first position, outside the elevator cabin <NUM>. Further, the second member <NUM> remains in engagement with the tray <NUM> when the tray <NUM> is moved between the first position and the second position.

Referring again to <FIG>, each tray <NUM> includes a base <NUM>, front end <NUM>, a rear end <NUM>, a rear wall <NUM> arranged at the rear end <NUM>, and two side walls <NUM>, <NUM>. The rear wall <NUM> and the sidewalls <NUM>, <NUM> extend substantially perpendicular to the base <NUM> and together define a tray chamber <NUM> to receive and store one or more postal items <NUM>. In an embodiment, the tray <NUM> includes a front opening <NUM> through which the postal item <NUM> from the tray <NUM> is discharged. Moreover, the rear wall <NUM> defines a plurality of openings <NUM> (herein after referred to as rear openings <NUM>) extending along an entire height of the rear wall <NUM> from the base <NUM> of the tray <NUM>. The rear openings <NUM> facilitate an insertion or extension of a flap member <NUM> (shown in <FIG>) inside the tray <NUM> to cause a removal of the postal item <NUM> from the tray chamber <NUM> through the front opening <NUM> when the tray <NUM> is pushed back into the elevator cabin <NUM>. Further, the tray <NUM> may include a plurality of ridges <NUM> or protrusions extending upwardly from the base <NUM>. Owing to the ridges <NUM>, the postal item <NUM> stored inside the tray chamber <NUM> remains lifted off the base <NUM> of tray <NUM>, enabling an easy removal of the postal item <NUM> from the tray <NUM> since a contact area between the tray <NUM> and the postal item <NUM> will be smaller. Also, the tray <NUM> may include an engagement structure <NUM> connected to the sidewall <NUM> and extending outwardly, in width-wise direction, of the tray <NUM>. The engagement structure <NUM> may be disposed outside the elevator cabin <NUM> when the tray <NUM> is at the first position, and may be arranged proximate to the front end <NUM> of the tray <NUM>.

As best shown in <FIG>, the engagement structure <NUM> may be a horizontally disposed U shaped structure and may define a recess <NUM> to receive the second member <NUM> of the hook member <NUM>. The second member <NUM> of the hook member <NUM> is adapted to engage with the engagement structure <NUM> to pull the tray <NUM> out of the elevator cabin <NUM>. Further, the recesses <NUM> of the trays <NUM> arranged inside the elevator cabin <NUM> are vertically in-line with each other. Accordingly, the second member <NUM> (i.e. the hook member <NUM>) remains disengaged from the trays <NUM> and passes through the recesses in the trays <NUM> as the elevator cabin <NUM> moves up and down. In this manner, the hook member <NUM> remains stationary while the trays <NUM> move up and down. Also, as the second member <NUM> remains inside the recess <NUM> of the tray <NUM> arranged in the first position and in alignment with the tray displacing mechanism <NUM>, the tray <NUM> can be quickly moved out of the elevator cabin <NUM> by actuating the drive belt <NUM>. Upon actuation of the drive belt <NUM>, the second member <NUM> of the hook member <NUM> engages with the engagement structure <NUM> and pulls the tray <NUM> outside the elevator cabin <NUM>. Further, the second member <NUM> of the hook member <NUM> remains in engagement with the engagement structure <NUM> when the tray <NUM> is disposed at the second position, and pushes the tray <NUM> to the first position when the drive belt <NUM> is moved towards the elevator assembly <NUM>.

Further, as shown in <FIG>, the sorting module may include an alignment block <NUM> disposed proximate to an upper end of the elevator frame <NUM> and above the tray displacing mechanism <NUM>. The alignment block includes a curved surface <NUM> facing front ends <NUM> of the trays <NUM> arranged inside the elevator cabin <NUM>. The alignment block <NUM> is arranged such that as the trays <NUM> move up and down with the elevator cabin <NUM>, front edges of the trays <NUM> may come into contact with the curved surface <NUM> of alignment block <NUM> and are pushed into the elevator cabin <NUM> into the proper position. In this way, it is ensured that the trays <NUM> while moving up and down will be in the correct position so that the engagement structure <NUM> of the tray <NUM> does not come into conflict with the hook member <NUM>.

Referring back to <FIG>, the sorting module <NUM> includes the flap member <NUM> that is arranged outside the elevator cabin <NUM> and adjacent to the front end <NUM> of the tray <NUM> when the tray <NUM> located at the first position. The flap member <NUM> is adapted to displace, for example, rotate between an engaged position (shown in <FIG> and <FIG>) and a free position (shown in <FIG> and <FIG>). In the engaged position, the flap member <NUM> extends vertically downwardly and may be disposed substantially parallel to front edges of the trays <NUM>, while in the free position, the flap member <NUM> may be disposed at an inclination relative to the horizontal and vertical direction. In an embodiment, in the engaged position, the flap member <NUM> is adapted to contact/engage with the postal item <NUM> stored inside the tray chamber <NUM> when the tray <NUM> is pushed back inside the elevator cabin <NUM>, while in the free position, the flap member <NUM> is disposed away from the tray <NUM> such that the tray <NUM> can be pushed into the elevator cabin <NUM> without having the flap member <NUM> come into contact with a postal item <NUM> stored in the tray <NUM>. Also, in the engaged position, the flap member <NUM> is adapted to be located behind a postal item <NUM> disposed inside the tray <NUM>, when the tray <NUM> is arranged at the second position to facilitate a removal of the postal item <NUM> from the tray <NUM>.

In an embodiment, the flap member <NUM> may include a plurality of flaps <NUM> (best shown in <FIG> and <FIG>) arrayed linearly and disposed spaced apart from each other. In the engaged position of the flap member <NUM>, the flaps <NUM> extend vertically downwardly and may extend substantially parallel to the rear wall <NUM> of the tray <NUM>, while in the free position, the flaps <NUM> may extend at an inclination relative to the vertical and are disposed away from the tray <NUM>. Further, in the engaged position of the flap member <NUM>, the plurality of flaps <NUM> may be aligned with the plurality of rear openings <NUM> (as shown in <FIG> and <FIG>) to facilitate an insertion of the flaps <NUM> inside the tray chamber <NUM> though the rear openings <NUM>. In some embodiments, in the engaged position of the flap member <NUM>, the flaps <NUM> are arranged behind the rear wall <NUM> of the tray <NUM> so that the flaps <NUM> enter the tray chamber <NUM> through the rear openings <NUM> and push the postal item <NUM> out of the tray <NUM> when the tray <NUM> is moved back inside the elevator cabin <NUM>. The postal item <NUM> that is removed from the tray falls onto the output conveyor <NUM>. Further, in the engaged position, the flaps <NUM> may be arranged such that bottom edges <NUM> of the flaps <NUM> are located above an inner bottom surface <NUM> of the tray <NUM> located in the second position, but below upper surfaces <NUM> of the ridges <NUM> of the tray arranged at the second position.

Referring back to <FIG>, <FIG>, and <FIG>, the output conveyor <NUM> extends below the tray displacing mechanism <NUM> and is adapted to receive a postal item <NUM> discharged from the tray <NUM>. Further, the output conveyor <NUM> is attached or coupled to the bracket <NUM>. The output conveyor <NUM> is adapted to convey/transport the postal items <NUM> in a direction substantially perpendicular to the direction of movement of the input conveyor <NUM>. In an embodiment, the output conveyor <NUM> is adapted to move the postal items <NUM> along the width wise direction of the sorting module <NUM>. As shown in <FIG>, the output conveyor <NUM> includes a first portion <NUM> arranged beneath the tray displacing mechanism <NUM> and is adapted to receive the postal item <NUM> falling from the tray <NUM> through the cavity <NUM>, and a second portion <NUM> connected to the first portion <NUM> and extending outwardly and downwardly from the first portion <NUM>. As shown, the second portion <NUM> may extend at an inclination relative to the first portion <NUM> and may extend outwardly of the bracket <NUM> to facilitate a positioning of the second portion <NUM> beneath/below a first portion <NUM> of an output conveyor <NUM> of an adjacent/neighbouring sorting module <NUM>. In some embodiments, the first portion <NUM> and the second portion <NUM> may be substantially parallel and inline to each other, and/or may include two separate belts, instead of a single belt as in the current embodiment.

Further, the first portion <NUM> may include a first belt <NUM> to transport the postal items <NUM> to the second portion <NUM>, and the second portion <NUM> may include a second belt <NUM> to transport the postal items <NUM> received from the first belt <NUM> to an output belt <NUM> (shown in <FIG> and <FIG>) of the sorting machine <NUM>. Accordingly, the output conveyor <NUM> is adapted to hold a single postal item <NUM> in two positions, for example, a first buffer position and a second buffer position. In the first buffer position, the postal item <NUM> is disposed on the first portion <NUM>, while the postal item <NUM> is stored/disposed on the second portion <NUM> in the second buffer position. In this manner, the output conveyor <NUM> is adapted to hold two postal items <NUM> simultaneously. Further, the output conveyor <NUM> may include a gate <NUM> movable between a closed position and an open position and arranged at a distal end of the output conveyor <NUM>. In the closed position, the gate <NUM> prevents a transportation of the postal item <NUM> from the second portion <NUM> to the output belt <NUM>, while in the open position, the gate <NUM> allows a transport of the postal item <NUM> from the second portion <NUM> to the output belt <NUM>. It may be appreciated that an opening and a closing of the gate <NUM> and movement of the second belt <NUM> may be controlled by a controller of the postal sorting machine <NUM> to facilitate an ejection of the postal items <NUM> from the sorting machine <NUM> in correct and desired order. In one embodiment (not shown), a single belt is arranged at an inclination and is provided with two separately operatable gates, one gate at the end of the second portion <NUM> and one gate between the first portion <NUM> and the second portion <NUM>.

As shown in <FIG>, the output belt <NUM> of the sorting machine <NUM> is adapted to receive the postal items <NUM> from each of the sorting modules <NUM>, and extend along a width of each of the sorting modules <NUM>. It may be envisioned that the output belt <NUM> is arranged/mounted beneath the second portions <NUM> of the output conveyors <NUM> of each of the sorting modules <NUM> to enable a receipt of the postal items <NUM> from each of the sorting modules <NUM>. Further, the sorting machine <NUM> includes an output station <NUM> to receive the postal items <NUM> from the output belt <NUM> in a correct and desired order.

A working of the sorting machine <NUM> is now described. At first, a stack of unsorted postal items <NUM> is brought to the sorting machine <NUM>, and is positioned proximate to the input station <NUM>. Thereafter, the postal items <NUM> are placed on the loading conveyor <NUM> one by one. In an embodiment, a robotic gripper may lift the unsorted postal items <NUM> and put the postal items <NUM> on the loading conveyor <NUM> one by one. In some other implementations, a person may add the postal items <NUM>, one at a time, to the loading conveyor <NUM>. It may be appreciated that postal items <NUM> are placed on the loading conveyor <NUM> with the address facing up. Subsequently, each postal item <NUM> passes through the scanner <NUM> where the address marked on each postal item <NUM> is photographed and then analysed to determine the correct address of delivery. In an embodiment, the address is determined using text recognition techniques known in the art. In some cases, the address written on one or more of the postal items <NUM> may not be determined accurately by the controller. Such postal items <NUM> are still stored in the sorting machine <NUM> and a human operator can later on read the address via a photograph of the postal item and type in the correct address. As the location of the postal item is known to the controller (as described below), the correct address can then be associated with the postal item for proper sorting.

The loading conveyor <NUM> transports the postal items <NUM> to the transport conveyor <NUM> that transfers the postal items <NUM> to various sorting modules <NUM>. To facilitate the transfer of the postal items <NUM> to the sorting modules <NUM>, the individual transport belts <NUM> are hinged/pivoted to the pivot position to cause a drop of the postal items <NUM> onto the associated sorting modules <NUM>. It may be appreciated that only a single postal item <NUM> is dropped/transferred to one sorting module <NUM> at a time. Also, when the transport belt <NUM> swings/pivots up to the pivot position, the postal item <NUM> falls down onto the input conveyor <NUM> running perpendicular to the transport belt <NUM>. In this manner, the postal items are received by various input conveyors <NUM> of the various sorting modules <NUM>.

As described earlier, the input conveyor <NUM> can hold two postal items <NUM> simultaneously, one on the first portion <NUM> and one on the second portion <NUM>. Any postal item <NUM> from the transport conveyor <NUM> first falls on to the first portion <NUM>, i.e., in the first buffer position 200a. After receiving the postal item <NUM>, the input conveyor <NUM> is rotated/moved in the direction 'B' to move the postal item <NUM> to the second portion <NUM>, i.e. the second buffer position 200b. Thereafter, the input conveyor <NUM> is stopped, and a second postal item <NUM> is allowed to fall on the input conveyor <NUM> from the transport conveyor <NUM>. In this manner, the input conveyor <NUM> can store up to two postal items <NUM> at a time.

Upon positioning the postal item <NUM> on the second portion <NUM> (i.e. in the second buffer position 200b, an empty tray <NUM> is moved out of the elevator cabin <NUM>. For so doing, the elevator mechanism may move the elevator cabin <NUM> up and down to bring one of the empty tray <NUM> in the first position such that the empty tray is horizontally aligned with the tray displacing mechanism <NUM>. In the first position, the empty tray <NUM> is also vertically aligned with the input conveyor <NUM>. Accordingly, the second member <NUM> of the hook member <NUM> is arranged inside the recess <NUM> of the empty tray <NUM>. As soon as the empty tray <NUM> is in alignment with the tray displacing mechanism <NUM>, and hence arranged in the first position, the tray displacing mechanism <NUM> (i.e. drive belt <NUM>) is moved, causing the engagement of hook member <NUM> with the engagement structure <NUM>, and enabling a pulling of the empty tray <NUM> outside the elevator cabin <NUM>. The drive belt <NUM> is operated/moved until the empty tray <NUM> reaches the second position. In the second position, at least a portion of the tray <NUM> is arranged directly below/beneath an upper surface of the second portion <NUM> of the input conveyor <NUM>. After the empty tray <NUM> is arranged at the second position, the sorting machine <NUM> simultaneously starts and moves the input conveyor <NUM> and the empty tray <NUM> in the direction 'B' towards the elevator cabin. Movements or speeds of the input conveyor <NUM> and the drive belt <NUM>, and hence the empty tray <NUM>, is controlled such that the postal item <NUM> located on the input conveyor <NUM> leaves the input conveyor and is deposited inside the tray <NUM>. In such a case, the postal item <NUM> travels in the direction of travel of the empty tray <NUM>. In an embodiment, the input conveyor <NUM> and the empty tray <NUM> are moved at the same speeds so the postal item <NUM> stored in the second buffer position falls properly inside the moving empty tray <NUM>. In some embodiments, the speed of the empty tray <NUM> is less than <NUM>% slower or less than <NUM>% faster than the speed of the input conveyor <NUM>.

It should be noted that in certain cases, if two or more postal items have the same address, then the two or more postal items can be stored in the same tray. When adding a second postal item on top of a first postal item, the above described method of adding the postal item to the tray, will ensure that the second postal item is laid nicely on top of the first item, without any risk of the postal items getting into conflict with each other.

Upon receiving the postal item <NUM> inside the tray <NUM>, the tray <NUM> is pushed fully back inside the elevator cabin <NUM> by continuing to move the tray <NUM> in the direction 'B', while the input conveyor <NUM> is stopped after the discharge of the postal item <NUM> from the second portion <NUM>. Once the tray <NUM> having the postal item <NUM> is pushed back inside the elevator cabin <NUM>, the elevator <NUM> moves the elevator cabin <NUM> up or down to position a new empty tray <NUM> aligned with the input conveyor.

In this manner, all the postal items <NUM> are stored in various trays <NUM> of the various sorting modules <NUM>. It may be appreciated that the controller of the sorting machine <NUM> records the locations of the storage of all the postal items <NUM>. After loading the postal items <NUM> in the trays <NUM> is complete, the controller can then find the best delivery route and starts to eject the postal items <NUM> from the trays <NUM> according to the optimal delivery order.

To eject a postal item <NUM> from a tray <NUM> disposed inside the elevator cabin <NUM>, the tray <NUM> is vertically moved by the elevator mechanism such that the tray <NUM> is in alignment with the tray displacing mechanism <NUM>. The tray <NUM> is now in the first position and aligned with tray sliding mechanism <NUM> such that the second member <NUM> of the hook member <NUM> is disposed in the recess <NUM> of the engagement structure <NUM>. Thereafter, the drive belt <NUM>, and hence the linear actuator <NUM>, is moved in a direction towards the input conveyor <NUM> to facilitate a pulling of the tray <NUM> having the postal item <NUM> out of the elevator cabin <NUM> by the hook member <NUM>. Once the tray <NUM> is pulled completely out of the elevator cabin <NUM> and arranged at the second position, the flap member <NUM> is rotated to the engaged position from the free position. Accordingly, the flap member <NUM>, and hence the flaps <NUM>, are positioned in a vertically downward direction behind the rear wall <NUM> of the tray <NUM>. Also, in the engaged position, the flaps <NUM> are inline or aligned with the rear openings <NUM>. In some implementations, the flap member <NUM>, and hence the flaps <NUM>, enters the tray <NUM> through the rear openings <NUM> upon rotation/displacement of the flap member <NUM> to the engaged position. In such a case, the flap member <NUM> is positioned proximate to the rear wall <NUM> and behind the postal item <NUM> stored inside the tray <NUM>. Subsequently, the drive belt <NUM> is started and moved towards the elevator cabin <NUM> in the direction 'B' to push the tray <NUM> inside the elevator cabin <NUM>. As the tray <NUM> moves towards the elevator cabin <NUM>, the postal item <NUM> contacts the flap member <NUM>, restricting the movement of postal item <NUM> in the direction 'B' along with the tray <NUM>, causing the postal item <NUM> to be pushed out of tray <NUM> through the front opening <NUM> and fall down from the tray <NUM>. In this manner, the postal item <NUM> is discharged from the tray <NUM> and falls on the output conveyor <NUM> through the cavity <NUM>.

Accordingly, the first portion <NUM> of the output conveyor <NUM> receives the postal item <NUM> falling from the tray <NUM>. The postal item <NUM> is then transferred to the second portion <NUM> of the output conveyor <NUM> by moving the first belt <NUM> of the first portion <NUM>. Accordingly, the output conveyor <NUM> can hold/store a postal item <NUM> in two positions, the first buffer position on the first portion <NUM> and the second buffer position on the second portion <NUM>. Due to the movement of the postal item <NUM> to the second portion <NUM>, the first portion <NUM> is ready to receive another postal item <NUM> from the elevator cabin <NUM>. Accordingly, the sorting machine <NUM> may keep operating the elevator cabin <NUM>, the trays <NUM>, the tray displacing mechanism <NUM>, and the flap member <NUM> to discharge/deliver another postal item <NUM> to first portion <NUM> of the output conveyor <NUM>, while one postal item <NUM> is waiting to be ejected from the second portion <NUM> of the output conveyor <NUM>. Thereby, the sorting machine <NUM> facilitates a faster sorting and discharge of the postal items <NUM>.

The postal item <NUM> stored on the second portion <NUM>, i.e., in the second buffer position, of the output conveyor <NUM> is moved to the output belt <NUM> by opening the gate <NUM> and moving the second belt <NUM>. It may be envisioned that the postal item <NUM> is stored on the second portion <NUM>, i.e. in the second buffer position, to deliver the postal item <NUM> in the correct order on the output belt <NUM>. Accordingly, the controller may keep a record of all the postal items <NUM> being delivered to the output belt <NUM> by all the sorting modules <NUM>, and starts the second belts <NUM> of the sorting modules <NUM> such that the postal items <NUM> are arranged on the output belt <NUM> in a desired sequence/order. The output belt <NUM> transports the postal items <NUM> in the correct sequence to the output station <NUM>. At the output station <NUM>, the postal items <NUM> are bundled into a stack by a worker and transferred to a delivery station.

It is to be noted, that depending on the speed of the sorting machine <NUM> and how many postal items <NUM> there are in a postal route, it is possible to start loading the postal items <NUM> from a second route into the sorting machine <NUM>, while the postal items <NUM> from a first route are being ejected from the sorting machine <NUM>. In this way, the sorting machine <NUM> can be working on two postal routes at the same time.

Claim 1:
A sorting machine (<NUM>) for automatically sorting a plurality of postal items, the sorting machine comprising:
a plurality of sorting modules (<NUM>) , each sorting module including:
an elevator assembly (<NUM>) having an elevator frame (<NUM>), an elevator cabin (<NUM>) movably supported by the elevator frame, a plurality of trays (<NUM>) arranged as a vertical stack of trays inside the elevator cabin, and an elevator mechanism (<NUM>,<NUM>) arranged to move the elevator cabin up and down in a vertical direction relative to the elevator frame, wherein each tray is adapted to be displaced with respect to the elevator cabin between a first position and a second position, the first position being inside the elevator cabin and the second position being at least partially outside the elevator cabin in a horizontal direction; and
an input conveyor (<NUM>) arranged at a fixed vertical position with respect to the elevator assembly,
said elevator mechanism being arranged to move the vertical stack of trays up and down to selectively bring at least one tray into vertical alignment with said input conveyor to facilitate a transport of a postal item (200a,200b) disposed on the input conveyor to the tray which is in vertical alignment with the input conveyor,
characterized in that:
the sorting machine is arranged to transfer a postal item from the input conveyor to the vertically aligned tray by first moving said tray outside the elevator cabin to the second position where the tray is disposed, at least partly, beneath an upper surface of the input conveyor and subsequently simultaneously operating the input conveyor and displacing the tray in a direction of movement of the input conveyor to the first position such that a postal item leaves the input conveyor and is deposited on the tray while the postal item is travelling in the same direction as the tray.