GB2085830A

GB2085830A - Conveyor systems with reduced speed of receptacles at loading stations

Info

Publication number: GB2085830A
Application number: GB8034441A
Authority: GB
Original assignee: Plessey Co Ltd
Current assignee: Plessey Co Ltd
Priority date: 1980-10-25
Filing date: 1980-10-25
Publication date: 1982-05-06
Also published as: GB2085830B

Abstract

A conveyor system e.g. for a postal sorting office incorporates a speed reduction arrangement to enable manual loading of the conveyor with parcels or packages. The conveyor has a plurality of separate endless chain drives which are driven in synchronism by a common drive means (3). The drive chains are attached to trays which travel in sequence along a common sorting path (2) and the attachment of the drives is such that each is separately attached successively to every Nth tray (1) along the sorting path (2) where N is the number of separate drives. The chains, are arranged to be separated into N separate loading loops e.g. (4); (5); (6), and (7), where the trays (1) travel at reduced speed due to a slackening of the chain drive to bunch the trays; the chain drives being accelerated where they come together again on the sorting path. <IMAGE>

Description

SPECIFICATION Conveyor systems The present invention relates to conveyor systems.

The The invention finds particular utility in high-speed conveyor systems, for instance, those used in a postal sorting machine employed at a postal sorting office. Items, such as packages or parcels are normally carried along conveyors in pockets or trays at high-speeds, and the conveyors incorporating the trays require to be loaded by placement of an item in each position accurately.

The speed of the conveyor is normally such that this can not be achieved manually. Accordingly, loading systems are used to enable several operators to work at a slower speed in parallel and then for transfer systems to load the high-speed conveyor. The items are automatically unloaded into sacks spaced along a common sorting path.

An aim of this invention is to provide a conveyor system which incorporates arrangements for temporarily reducing the speed at the item loading stations in order to enable direct manual loading.

According to the present invention, there is provided a conveyor system incorporating speed reduction arrangements, the conveyor system comprising a plurality of individual endless drive means adapted to be driven in synchronism, and a plurality of recepticles arranged in sequence along a common path, and the individual drive means are each separately attached successively to every Nth recepticle along the common path of the system, where N is the number of drive means, and each recepticle is attached to no more than one drive means, the system being so arranged that the drive means travel together along the common path, and the drive means are so adapted as to enable their separation into individual loops at loading stations, thereby reducing the speed of the recepticles at the loading stations by a factor of S/N, where S is the speed of the conveyor along the common path.

The invention will be better understood from the following description of an exemplary embodiment which should be read in conjunction with the accompanying drawings in which: Figure 1 shows a plan view of the conveyor system incorporating the speed reduction arrangements; Figure 2 shows an end view of two recepticles (or trays) attached to two separate drive means at the loading stations; Figure 3 shows an end view of the same two recepticles (or trays) as they appear together along the common path (at point 'A' in Figure 1) and, Figure 4 shows a side view of the conveyor at a loading station.

Referring now to the drawings, the drive means of the conveyor system as shown takes the form of an endless chain and in the system shown, there are four such endless chains, each individual one of which is separately attached, successively, to every fourth recepticle, taking the form of a tray 1, along a common sorting path 2, with each tray being attached to no more than one drive means.

The four chains, which are driven in synchronism by a common driving means 3, travel together along the common sorting path 2 of the system, the trays moving along the common path in sequence. At the entrance to the loading stations the chains are separated into four separate loops 4, 5, 6 and 7 of identical length to permit separate access to each chain, and the trays attached thereto, for loading purposes.

If a single loading station is considered, as shown in Figure 4 it can be seen that at the entrance to the loading station the trays are travelling at the high speed of the sorting path but are spaced apart, with three tray-lengths between each tray. It should be appreciated that the drive keeps the chain taut at the entrance to the loading station, however, it slackens between the trays, as at 8 during its passage through the station. Between the entrance and the exit of the loading station the trays are constrained and tend to form a stack so that each tray touches its adjacent tray. In this way the trays are driven through the station at one quarter of the speed of the trays travelling along the common sorting path 2.

At the exit of the station the chain is tightened again as it runs over an idler 9, whereupon it accelerates to full-speed again carrying the trays with it.

In Figure 2 it is shown (as viewed end-on) how two trays 1 and la are situated on two separate chains as they travel around two separate loops of the loading stations. In Figure 3 the two trays 1 and 1a are shown to come together at point A (Figure 1) at the exit from the loading stations as they enter the common sorting path 2.

This invention enables either direct manual loading of trays, or the use of very simple loaders. The number of moving parts is reduced which provides a higher reliability at a lower cost.

Additionally, in the control area, the task is much simpler, as once the package is loaded there is no further transfer required for identification or registration. It should be understood that the invention is not limited to the use of chain drives, other types of drive means can be utilised, but they must be flexible to enable them to slacken when not under tension.

While the invention employs four chain drives, it is possible for fewer or more chains to be used; the attachment of the chains to the trays being naturally dictated by the number of chains employed i.e. if two chains were used each chain would be required to be attached to every second tray, and if six chains were used each chain would be required to be attached to every sixth tray, and so on.

In each of these examples the speeds of the trays at the loading stations would be reduced by one half and one sixth respectively.

1. A conveyor sytem incorporating speed reduction arrangements, the conveyor system comprising a plurality of individual endless drive means adapted to be driven in synchronism, and a plurality of recepticles arranged in sequence along a common path, and the individual drive means are each

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Conveyor systems The present invention relates to conveyor systems. The The invention finds particular utility in high-speed conveyor systems, for instance, those used in a postal sorting machine employed at a postal sorting office. Items, such as packages or parcels are normally carried along conveyors in pockets or trays at high-speeds, and the conveyors incorporating the trays require to be loaded by placement of an item in each position accurately. The speed of the conveyor is normally such that this can not be achieved manually. Accordingly, loading systems are used to enable several operators to work at a slower speed in parallel and then for transfer systems to load the high-speed conveyor. The items are automatically unloaded into sacks spaced along a common sorting path. An aim of this invention is to provide a conveyor system which incorporates arrangements for temporarily reducing the speed at the item loading stations in order to enable direct manual loading. According to the present invention, there is provided a conveyor system incorporating speed reduction arrangements, the conveyor system comprising a plurality of individual endless drive means adapted to be driven in synchronism, and a plurality of recepticles arranged in sequence along a common path, and the individual drive means are each separately attached successively to every Nth recepticle along the common path of the system, where N is the number of drive means, and each recepticle is attached to no more than one drive means, the system being so arranged that the drive means travel together along the common path, and the drive means are so adapted as to enable their separation into individual loops at loading stations, thereby reducing the speed of the recepticles at the loading stations by a factor of S/N, where S is the speed of the conveyor along the common path. The invention will be better understood from the following description of an exemplary embodiment which should be read in conjunction with the accompanying drawings in which: Figure 1 shows a plan view of the conveyor system incorporating the speed reduction arrangements; Figure 2 shows an end view of two recepticles (or trays) attached to two separate drive means at the loading stations; Figure 3 shows an end view of the same two recepticles (or trays) as they appear together along the common path (at point 'A' in Figure 1) and, Figure 4 shows a side view of the conveyor at a loading station. Referring now to the drawings, the drive means of the conveyor system as shown takes the form of an endless chain and in the system shown, there are four such endless chains, each individual one of which is separately attached, successively, to every fourth recepticle, taking the form of a tray 1, along a common sorting path 2, with each tray being attached to no more than one drive means. The four chains, which are driven in synchronism by a common driving means 3, travel together along the common sorting path 2 of the system, the trays moving along the common path in sequence. At the entrance to the loading stations the chains are separated into four separate loops 4, 5, 6 and 7 of identical length to permit separate access to each chain, and the trays attached thereto, for loading purposes. If a single loading station is considered, as shown in Figure 4 it can be seen that at the entrance to the loading station the trays are travelling at the high speed of the sorting path but are spaced apart, with three tray-lengths between each tray. It should be appreciated that the drive keeps the chain taut at the entrance to the loading station, however, it slackens between the trays, as at 8 during its passage through the station. Between the entrance and the exit of the loading station the trays are constrained and tend to form a stack so that each tray touches its adjacent tray. In this way the trays are driven through the station at one quarter of the speed of the trays travelling along the common sorting path 2. At the exit of the station the chain is tightened again as it runs over an idler 9, whereupon it accelerates to full-speed again carrying the trays with it. In Figure 2 it is shown (as viewed end-on) how two trays 1 and la are situated on two separate chains as they travel around two separate loops of the loading stations. In Figure 3 the two trays 1 and 1a are shown to come together at point A (Figure 1) at the exit from the loading stations as they enter the common sorting path 2. This invention enables either direct manual loading of trays, or the use of very simple loaders. The number of moving parts is reduced which provides a higher reliability at a lower cost. Additionally, in the control area, the task is much simpler, as once the package is loaded there is no further transfer required for identification or registration. It should be understood that the invention is not limited to the use of chain drives, other types of drive means can be utilised, but they must be flexible to enable them to slacken when not under tension. While the invention employs four chain drives, it is possible for fewer or more chains to be used; the attachment of the chains to the trays being naturally dictated by the number of chains employed i.e. if two chains were used each chain would be required to be attached to every second tray, and if six chains were used each chain would be required to be attached to every sixth tray, and so on. In each of these examples the speeds of the trays at the loading stations would be reduced by one half and one sixth respectively. CLAIMS

1. A conveyor sytem incorporating speed reduction arrangements, the conveyor system comprising a plurality of individual endless drive means adapted to be driven in synchronism, and a plurality of recepticles arranged in sequence along a common path, and the individual drive means are each separately attached successively to every Nth recepticle along the common path of the system, where N is the number of drive means, and each recepticle is attached to no more than one drive means, the system being so arranged that the drive means travel together along the common path, and the drive means are so adapted as to enable their separation into individual loops at loading stations, thereby reducing the speed of the recepticles at the loading stations by a factor of S/N, where S is the speed of the conveyor along the common path.

2. A conveyor system as claimed in claim 1, in which the recepticles are trays, and between the entrance and the exit of each loading station the endless drive means becomes slack and the trays are constrained, thereby forming a stack so that each tray touches its adjacent tray driving its forward tray through the station at the reduced speed.

3. A conveyor system as claimed in claim 2, in which at the exitfrom each loading station the endless drive means co-operates with an idler which enables the endless drive means to become taught thereby carrying the trays associated with it at the speed of the common path.

4. A conveyor system as claimed in claim 2 or 3, in which the endless drive means are endless chains which co-operate with a common drive means at the entrance to the loading stations.

5. A conveyor system as claimed in claim 4, in which there are four endless chains, enabling the speed of the trays attached to any chain as it travels between the entrance and exit of a loading station to be one quarter of the speed of a tray travelling along the common path.

6. A conveyor system as claimed in any preceding claim for use in a postal sorting machine and in which the loading stations are employed for manual loading of parcels and/or packets into the recepticles and the common path is a common sorting path for automatically unloading the packets and/or parcels into sacks.

7. A conveyor system substantially as described herein, with reference to, and as shown, in the accompanying drawings.

8. A postal sorting machine including a conveyor system substantially as described herein, with reference to, and as shown, in the accompanying draw ings.