GB2240530A

GB2240530A - Conveyor belt for a sorting conveyor

Info

Publication number: GB2240530A
Application number: GB9102332A
Authority: GB
Inventors: Terence Mcgee
Original assignee: National Conveyors Co
Current assignee: National Conveyors Co
Priority date: 1990-02-03
Filing date: 1991-02-04
Publication date: 1991-08-07
Also published as: GB9102332D0

Abstract

A sorting conveyor includes a belt 2 which carries along its length and at spaced intervals therealong a plurality of upstanding members or flights 6 adapted to limit relative movement between said belt and items placed thereon, means being provided on said belt to maintain said belt in its correct tracking position relative to support structure of said conveyor. The conveyor includes a length of trunking 14 which, over a predetermined length of travel of the belt, supports the belt and transposes the belt from a horizontal path of travel to an inclined path of travel and returns it to said horizontal path of travel. The belt preferably carries bracing rollers 18 which run in a groove 20 in the trunking 14. <IMAGE>

Description

Belt Conveyors This invention relates to belt conveyors and more particularly to belt conveyors known as sorting conveyors.

A sorting conveyor is the type of conveyor used in the distribution of parcels and packages and other items where the items to be despatched to different locations are fed onto the conveyor, usually at one end thereof, pass along the conveyor, and then leave the conveyor at differing points along the length thereof, the point of leaving the conveyor being determined by the ultimate destination of the item.

To properly have the items leave the conveyor at the correct point, the conveyor is laterally inclined at a number of locations along its length so that when a gate or flap is opened an item may leave the conveyor. Such lateral inclination of the conveyor is normally set at a maximum angle of inclination of 37 degrees, but it has been found that in many instances this angle of inclinat ion is insufficient to to ensure that the item leaves the conveyor as required, due in no small way to the friction between the item and the belt of the conveyor.

The angle of inclination of 37 degrees alone the relative length of the conveyor is the maximum that has been possible, because at greater angles of inclination the belt of the conveyor due to its weight.and its tracking, binds on the support structure of the conveyor causing damage to the said structure and damage and edge wear of the belt itself.

In the use of sorting conveyors, it is often the case that items to be despatched are 'timed out' as they pass along the conveyor so that the items leave the conveyor at the required location relative to the length of the conveyor, such that the items are directed to the correct point for onward despatch, but it has been found that the items very often move relative to the conveyor - due primarily to friction considerations - as well as with the conveyor. If the items move sufficiently relative to the conveyor, then by the time the belt reaches the point for the item to leave the conveyor, the items are not on the correct 'length section' of belt and hence do not leave the conveyor at the correct and required location.

This often requires the relocation and redirection of the item which is both time-consuming and costly.

The present invention therefore seeks to provide an improved sorting conveyor which will overcome the many disadvantages of known sorting conveyors.

According to the present invention there is provided a sorting conveyor including a belt carrying along its length and at speced intervals therealong a plurality of upstanding members or flights adapted to limit relative movement between the belt and items placed thereon, means being provided on said belt to maintain said belt in its correct tracking position relative to support structure of said conveyor.

Said members or flights will preferably be of rectangular cross-sectional shape and will preferably be composed of plastics material. Each member or flight will preferably be provided with one or more inserts adapted to bear on support structure of said conveyor during the return run or flight of the conveyor.

Said conveyor will preferably include a length of trunking which, over a predetermined length of travel of said belt, transposes said belt from a horizontal path of travel to an inclined path of travel and returns it to the horizontal path of travel and which supports said belt during its lenght of inclined travel.

Said belt, on its surface opposite to that carrying the members or flights, will preferably carry one or more tracking rollers which engage in a groove or rail in said trunking so as to maintain the desired lateral position of said belt relative to said trunking.

Said trunking will preferably include a plurality of flaps or gates which are movable from a first position to a second position to allow an item on said belt to leave said belt through an opening created when an appropriate flap or gate moves to said second position.

Preferably, said trunking will carry support structure for supporting the return flight or run of said belt, said support structure including one or more horizontal support bars adapted to be engaged by the inserts in the members or flights during said return flight or run of said belt.

The conveyor will preferably include means to tension a belt drive roller of said conveyor.

In order that the invention may be more readily understood, an embodiment thereof will now be described, by way of example, reference being made to the accompanying drawings, wherein: Figure 1 is a cross-section of part of a sorting conveyor in accordance with the invention; Figure 2 is a cross-section of a further part of the conveyor; Figure 3 is a perspective view of part gf Figure 2; Figure 4 is a cross-sectional elevation, to a larger scale, of part of Figure 2; Figure 5 is a perspective view of one end of the conveyor in accordance with the invention and shows means for adjusting the tension of the belt of the conveyor; and Figure 6 is a partial end view of the arrangement shown in Figure 5.

Referring to the drawings, the sorting conveyor includes a belt 2 which passes around a series of drums at the ends of the conveyor. One of these drums, i.e. the driven drum, is indicated by reference numeral 4.

The belt 2 carries a plurality of upstanding members or flights 6 which are secured to the belt at predetermined intervals along its length by means of bucket bolts 8 which will preferably be 'capped off' after fitting. The members or flights 6, which will preferably be composed of synthetic plastics material such as polyurethane, each have bearing inserts 10 therein, these inserts preferably being composed of Nylon (RTM) or other suitable material.

The conveyor includes a section which is inclined at an angle of 40 degrees to the horizontal, this being the section from which items placed on the belt are ejected as will be hereinafter explained. Referring then to Figures 2 and 3, Figure 2 shows a section 2A of the belt 2 at an inclined angle of 40 degrees to the horizontal, the belt passing from the horizontal to this angle of inclination over a length of approximately two metres.

This inclination is imparted to the belt by means which are located at one end of a length of trunking 14 which supports the belt during the length of its inclined travel. Further means at the opposite end of the trunking 14 return the belt, again over a length of approximately two metres, from its inclined disposition to a horizontal disposition. The horizontal dispositions are indicated by reference numerals 2 in Figure 3.

In order to prevent the belt moving laterally relative to the trunking 14 when the belt 2 is in its inclined disposition, and in order to maintain a central disposition of the belt 2 relative to the trunking 14, the belt 2 carries a number of tracking rollers 18 which run in a channel or groove 20 in the trunking, the rollers 18 being secured to the belt 2 on the opposite side or surface to the side or surface carrying the members or flights 6. Thus the belt - in the inclined disposition shown in Figure 2 - is maintained in the desired lateral position relative to the trunking 14 such that the belt will not move laterally relative to the trunking and thereby foul the support structure and cause damage thereto and to the belt.

Along the length of the trunking 14 is a plurality of flaps or gates - one is indicated by reference numeral 22 in Figure 2 - these flaps or gates being movable upon the receipt of a signal, as will be hereinafter explained, from the full line position to the phantom line position 22A in Figure 2 so as to allow an item on the conveyor belt to leave the belt through the opening created upon movement of the appropriate flap or gate.

To support the return flight or run of the belt 2, there is provided a support structure carried by the trunking 14, this structure comprising a frame 24 carrying horizontal support bars 26, these bars engaging in the notched inserts 10 of the members or flights 6. The support bars 26 are height adjustable so as to compensate for varying tension in the belt 2. Additionally, side bars are provided to support the side extremities of the return run of the belt, this support arrangement being shown in detail and to a greater scale in Figure 4.

Referring now to Figures 5 and 6, which show means for tensioning the conveyor drive roller 4, it will be seen that the drive roller, supported in structure 30, is connected through suitable connection means 32 to tensioning screws at either side of the conveyor - one of such tensioning screws is indicated by reference numeral 34. The tensioning screws 34 are connected to a common tie member 36 which carries pulley wheels 38 and 40 which, through belts 42 and 44, are connected to multigrooved pulley wheels 46 and 48. In turn, these pulley wheels 46 and 48 are interconnected by a belting arrangement 50, the ends of which carry weights, one of which is indicated at 52 in Figure 6.

A handwheel 54, a cross-section through which is shown in Figure SA, is locatable on spindles 38A and 40A of the pulley wheels 38 and 40. Thus by engaging the handwheel on the spindle 38A or 40A, the tension in the belt 2 may be adjusted, the arrangement of the handwheel mechanism enabling either side of the drive roller 4 to be moved and adjusted relative to the support structure, or both sides of the roller to be so adjusted, thus enabling the belt tension to be adjusted.

In use of a conveyor in accordance with the invention, items to be sorted are fed either by hand or by means of a conveyor or other means onto a feed-out device located at the leading end of the sorting conveyor. This feed-out device, not shown in the drawings, may comprise a sliding plate onto which an item to be sorted will be placed or fed, the plate retracting upon receipt of a signal so as to allow the item to fall onto the belt 2 of the conveyor. The plate will be retracted by means of solenoidoperated devices, by pneumatic means, or by means of gearing.

To facilitate the correct placement of an item on the belt 2 of the conveyor, i.e. in the correct space between the appropriate members or flights 6, the item - such as a parcel, a suitcase or other address-designated item will be scanned either by means of a scanner, a bar code reader, or visually, and the appropriate destination point will be selected so that when the appropriate member or flight 6 comes round, the sliding plate is retracted to allow the item to be located on the belt 2 and then proceed along the conveyor. When the appropriate flap or gate is reached, this flap or gate will be opened to allow the item to slide off the belt and into or onto the relevant subsequent handling point.The flaps or gates will preferably be pneumatically operated or solenoid operated, and proximity switches will be provided to ensure that the appropriate flap or gate to be opened is selected.

Although not shown in the drawings, means will be incorporated on the tail drum of the conveyor in order to compensate for the weight of the members or flights 6 and the belt on the return flight or run of said balt.

A conveyor in accordance with the invention ensures that the items to be conveyed and transferred to the relevant take-off point are maintained on the conveyor within preset limits so that the item will be transferred or ejected from the conveyor at the selected point. In addition, due to the provision of the support means for the return flight or run of the belt, this return flight or run is fully supported which lessens the tendency of the belt to stretch and hence decrease the tension in the belt with all the inherent disadvantages of such stretching.

The provision of the tracking roller(s) ensures the correct disposition of the belt relative to the trunking, in the inclined disposition of the belt, thus eliminating damage to the support structure of the conveyor and to the belt of the conveyor. The provision of the tracking roller(s) also allows the angle of inclination of the belt to be increased from the normal 37 degrees to 40 degrees, thus increasing the tendency of an item to leave the conveyor at the appropriate place.

The inserts in the members or flights 6 ensure a low friction, low noise conveyor.

It will be appreciated that the conveyor is of variable length.

It will also be appreciated that modifications may be made to a conveyor in accordance with the present invention without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

CLAIMS:

1. A sorting conveyor including a belt carrying along its length and at spaced intervals therealong a plurality of upstanding members or flights adapted to limit relative movement between said belt and items placed thereon, means being provided on said belt to maintain said belt in its correct tracking position relative to support structure of said conveyor.

2. A conveyor in accordance with Claim 1, wherein said members or flights are of rectangular cross-sectional shape and are secured to said belt at predetermined intervals therealong.

3. A conveyor in accordance with Claim 1 or Claim 2, wherein said members or flights are composed of synthetic plastics material and are each provided with one or more inserts which bear on support structure of the conveyor during the return flight or run of said belt.

4. A conveyor in accordance with any of Claims 1 to 3, wherein said conveyor includes a length of trunking which, over a predetermined length of travel of said belt, transposes said belt from a horizontal path of travel to an inclined path of travel and returns it to said horizontal path of travel and which supports said belt during the length of its inclined path of travel.

5. A conveyor in accordance with Claim 4, wherein said belt, on its surface opposite to that which carries the members or flights, carries one or more tracking rollers which engage in a groove or rail in said trunking so as to maintain the desired lateral position of said belt relative to said trunking.

6. A conveyor in accordance with Claim 4 or Claim 5, wherein said trunking includes a plurality of flaps or gates which are movable from a first position to a second position to allow an item on said belt to leave the belt through an opening created when an appropriate flap or gate moves to said second position.

7. A conveyor in accordance with Claim 6, wherein said flaps or gates are pneumatically operated or solenoid operated.

8. A conveyor in accordance with any of Claims 4 to 7, wherein said trunking carries support structure for supporting a return flight or run of said belt, said support structure including one or more horizontal support bars which is or are engaged by the inserts in the members or flights during said return flight or run of said belt.

9. A conveyor in accordance with Claim 8, wherein said support bars are height adjustable to compensate for varying tension in said belt.

10. A conveyor in accordance with Claim 8 or Claim 9, wherein said support structure includes side bars for supporting the side extremities of the return flight or run of said belt.

11. A conveyor in accordance with any of Claims 1 to 10, including a belt drive roller and means to adjustably tension said roller, said means enablimg the roller to be adjustably tensioned at each end thereof either independently or simultaneously.

12. A conveyor in accordance with Claim 11, wherein said means include tensioning screws which are connected to a common tie member carrying pulley wheels which are connected to multi-grooved pulley wheels through the intermediary of a belting arrangement, ends of which carry weights.

13. A sorting conveyor constructed and adapted to operate substantially as herein described with reference to and as illustrated in the acconpanying drawings.