GB2138376A - Conveyor chains - Google Patents

Abstract

A conveyor chain (1) has pivotally interconnected link structures (6) with upstanding longitudinally extending side-by-side ribs (7, 8) which define the conveying surface. Occasional ones of the link structures have pusher ribs (8) which project to a greater height. All ribs (7, 8) run between fingers (15) of a take-off surface (16) and the pusher ribs (8) act to push conveyed goods onto and along the fingers (15). <IMAGE>

Description

SPECIFICATION Conveyor chains This invention relates to conveyor chains of the kind, hereinafter referred to as the kind defined, comprising a plurality of pivotally interconnected link structures having longitudinally extending side-by-side ribs with exposed upper peripheral edges which collectively define a supporting surface for products to be conveyed.

With conveyor chains of the kind defined the ribbed supporting surface advantageously reduces drag and wear on the conveyed product and, especially where the surface is of slatted form having through gaps or slots between the ribs, the chain is particularly suitable for use in washing and cooling conveyors as well as accumulators and simple conveyors.

However, in certain applications it is important to ensure that the conveyed product is firmly located, as for example in the case where a desired spacing or pitch is to be maintainedforfilling or other purposes with indexing conveyors, or in the case where the conveying path is inclined and product slippage is to be avoided, and problems can arise in this respect with known chains of the kind defined with which the said supporting surface is generally of a smooth and planar configuration.Also, where the chain is used to deliver goods to a take-off surface, in order to ensure smooth and steady transfer the ribs are required to run as closely as possible up to a leading edge of such surface and there is therfore the problem of achieving this whilst avoiding accidental injury to personnel employed in handling goods delivered by the conveyor, or damage to goods, due to the nip or scissor action between the ribs and the take-off surface edge.

An object of the present invention is to provide a ribbed conveyor chain with which the abovementioned problems can be avoided or at least appreciably reduced.

According to th e i the inventionthereforethere is provided a conveyor chain of the kind defined characterised in that some said ribs project above longitudinally adjacent other said ribs.

With this arrangement, the said projecting ribs can act as stops which facilitate traction with conveyed products whereby accurate indexing and secure retention on an inclined conveying path can be readily achieved.

Also, there is the possibility of achieving smooth transfer of goods off the conveyor chain onto a take-off surface without undue risk of personnel injury or product damage in so far as the projecting ribs can act to push the transferred goods smoothly onto the take-off surface while the remaining ribs run at a lower level and do not define a dangerous nip with the said surface. In this respect, in a particularly preferred embodiment, the chain is used with a take-off surface having a leading edge structure defined by fingers, the said pusher ribs being arranged to run up to and between the fingers projecting thereabove whilst the other ribs are generally at or below the fingers, the said projecting and other ribs then being arranged to follow a curved path through and away from the fingers.

Appropriately inclined or curved faces associated with the take-off surface may be provided between the fingers, and the arrangement may be such that the projecting ribs run in close proximity to such faces whilst the other ribs are well spaced therefrom, thereby to give ease of transfer of goods onto and beyond the fingers whilst minimising the risk of injury or damage due to a nip or scissor action between the conveyor chain and the take-off surface.

The link structures of the chain may each comprise a plurality of side-by-side ribs, preferably with longitudinally extending through slots therebetween, united along opposite ends thereof with hinge or pivot formations for interconnection with cooperable such formations on adjacent said structures. Preferably, each structure has a single set of ribs of a common kind (i.e. projecting or otherwise) and the ribs may be of a common height such that the top peripheral edges thereof define a planar surface. Preferably also the chain is made up wholly or mainly of only two kinds of ribs: the said projecting ribs which may all have a respective common height, and the said other ribs which may also have a respective common height. The relative frequency and longitudinal spacing of the respective kinds of ribs may be selected as desired and in accordance with the product to be conveyed.In one embodiment there may be three sets of nonprojecting ribs between each pair of successive sets of projecting ribs.

The chain may be used in a conveyor in which the chain is passed around one or more driven sprockets in conventional manner.

The invention will now be described further by way of example only and with reference to the accompanying drawings in which: Figure 1 is a diagrammatic sectional view of part of a conveyor incorporating one form of a conveyor chain according to the invention; Figure 2 is a plan view of one link of the conveyor chain; Figure 3 is a plan view of a finger plate of the conveyor as shown in Figure 1; and Figure 4 is a side view of the plate of Figure 3.

A conveyor which may be used for example for delivering products to a packaging table comprises a conveyor chain 1 which runs through a closed path around sprockets 2, at least one of which is driven, with upper and lower horizontal runs 3, 4. The upper run 3 extends between a loading location (not shown) at which products are placed on the surface of the chain 1, and a delivery location at which the conveyed products are transferred off the chain onto a packing table 5.

The chain 1 comprises a plurality of pivotally interconnected link structures 6 each of which constitutes a one-piece plastics moulding of elongate form having a plurality of upstanding parallel ribs 7 or 8 with through slots 9 therebetween and united at the leading and trailing long edges of the structure with hinge formations 10,11. Each hinge formation 10 is of cooperable configuration to the adjacent hinge formation 11 of the next adjacent link structure 6 in the chain 1 and such formations 10, 1 comprise tubular parts through which a stainless steel pivot pin 12 is inserted.

The upstanding ribs 7, 8 of each structure have flat top edges 13, or 14 which extend horizontally in the top run 3 of the chain and the ribs 7 or 8 of each structure have a common heighttherebydefining collectively a respective flat, horizontal supporting surface.

As shown in Figure 1, there are two such common heights and between each pair of successive link structures 6 having the taller ribs 8 there are three link structures 6 having the smaller ribs 7. The structures 6 have a common width which may be selected as desired say in the range 6" to 48" in 6" steps (i.e. 15cm to 122cm in 15cm steps).

At the leading end of the top run the upstanding ribs 7,8 of the links 6 pass between freely projecting horizontal fingers 15 of a finger plate 16 fixed to the packing table 5. The fingers 15 are paral lel,-appropri- ately spaced to fit with good clearance between each pair of adjacent ribs 7 or 8, have chamfered free-ends 17, and are fixed at their opposite ends to an integral flat, horizontal base plate 18.Between the fingers 15 the base plate is chamfered to provide an inclined downwardly directed surface 19 As shown in Figure 1, in the top horizontal run 3, the top edges 13 of the smaller ribs 7 terminate level with or slightly above the horizontal planecontain- ing the top surfaces of the fingers 3 .15. and the base plate 18 whereas the taller ribs 8 project appreciably above this plane. The chain 1 passes around the associated sprocket 2 as it moves from the top run 3 to the bottom run 4 and the ribs 7, 8 pass between the fingers 15 and then curve downwardly through same.It will be seen that the top edges 14 of the taller ribs 8 pass in close proximity (and generally parallel) to the inclined (or curved) faces 19 during this movement whereas the top edges.13 of the smaller ribs 7 are appreciably spaced therefrom.

With this arrangement, the tallerribs 8 a.ctas pusher ribs which engage products onthe chain 1 so as to ensure positive conveying thereof with easy noise-freetransferto the fingers 15 and from there to the packing table 5. Especially in the case where products are supported on the ribs 7 between the pusher ribs 8, the latter ribs 8 can engage the products with their leading side edges 20.and thereby give good traction whilst the products are maintained accurately in a desired horizontal dispostion and accurately at predetermined locations on the chain. Thereby product tipping and spilling can be avoided, especially at the.transfer location, and indexing can be readily maintained. Where the conveyor chain has an inclined run, the taller ribs 8 can limit or prevent product slipping.

Moreover, the smooth manner in which.the ribs 7, 8 pass between and through the fingers with the pusher ribs 8 running close to the faces 19 and the ribs 7 running close to the top surface of the fingers 15, limits the danger of injury to personnel and damage to goods caused by nip or scissor action.

It is of course to be understood.that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only.

Claims (11)

1. A conveyor chain of the kind defined characterised in that some said ribs project above longitudinally adjacent other said ribs.

2. A chain according to claim 1, wherein each link structure has through slots between the said sideby-side ribs thereof.

3. A chain according to claim 1 or 2, wherein the said side-by-side ribs of the link structures are united along opposite ends thereof with hinge or pivot formations interconnected with cooperable such formations on adjacent said structures.

4. A chain according to any one of claims 1 to 3, wherein each link structure has a single set of said ribs of a common kind, that is, projecting or otherwise.

5. A chain according to claim 4, wherein the said ribs of each link structure are of a common height such that the top peripheral edges thereof define a planar surface.

6. A chain according to any one of claims 1 to 5, which is made up wholly or mainly of only two kinds of said ribs, namely, the said projecting ribs which all have a respective common height and the said other ribs which also have a respective common height.

7. A chain according to claim 6, wherein there are three sets of said other ribs between each pair of successive sets of said projecting ribs.

8 A conveyor incorporating a chain according to any one of claims 1 to 7.

9. A conveyor according to claim 8, including a take-off surface having a leading edge structure defined by fingers, the said projecting ribs being arranged to run up to and between the fingers projecting thereabove whilst the other ribs are generally at or below the fingers, the ribs then being arranged to follow a curved path through and away from the fingers.

10. A conveyor according to claim 9, wherein inclined or curved faces are associated with the take-off surface between the fingers, the arrangement being such that the projecting ribs run in close proximity to such faces whilst the other ribs are well spaced therefrom.

11. A chain and a conveyor substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.