GB2385585A

GB2385585A - Method and apparatus for separating articles from a stack

Info

Publication number: GB2385585A
Application number: GB0204516A
Authority: GB
Inventors: John Nixon
Original assignee: ADVANCED FOOD TECHNOLOGY Ltd
Current assignee: ADVANCED FOOD TECHNOLOGY Ltd
Priority date: 2002-02-26
Filing date: 2002-02-26
Publication date: 2003-08-27
Also published as: GB0204516D0

Abstract

An apparatus for partially separating articles, such as slices of bread for sandwich preparation, comprises a pair of conveyor chains 15 which initially move downwardly to covey a stack of aligned slices towards an upwardly inclined transition region where the direction of movement of the slices changes to be upward. During the transition from the downward to the upward parts of the conveyor path the slices are conveyed by contact of their edges 21b with the conveyor chain 15 so as to fan out the slices by shearing action, as they follow a concave path, to allow them to be presented as a leading slice 3c and a next successive slice 3b separated sufficiently to facilitate removal of the end slice 3c from the stack.

Description

METHOD AND APPARATUS FOR SEPARATING ARTICLES FROM A STACK The present invention relates to a method of and apparatus for separating articles from a stack, and is particularly suitable for the separation of slices of food product moving to a delivery point in stack configuration.

There are various devices known for separating sheets of paper and other materials from a stack so as to allow the top sheet to be more readily removed at a delivery station, for example a sheet uptake position in an office printing machine or a photocopier.

The problem arises in other fields of having much more fragile articles which need to be separated, and one particular situation involves the separation of slices of food being advanced towards a station in which the end slice of a travelling stack is to be readily removable. One particularly relevant application for this action is in the presentation of slices of bread for automated sandwich preparation.

It is an object of the present invention to provide a method of and apparatus for permitting loading of a stack of articles for advancing towards a delivery station for presentation of the leading said article at a delivery point.

According to a first aspect of the present invention, there is provided a method of partially separating articles in a downwardly moving stack comprising deflecting a moving stack of the articles from a first downward direction to a second upward direction, and driving the stack from that side of the stack which faces radially outwardly of the region of deflection between the first and second directions, so as to fan out the articles before arrival at a delivery station.

Preferably, the articles are slices of bread being presented as a stable stack at said delivery station.

A second aspect of the present invention provides an apparatus for partially separating articles in a moving stack, comprising a concave surface provided with a conveyor means following the path of the concave surface and able to be driven initially in a downward first direction along the surface and then reach an upward second direction after a point of deflection of the conveyor means while following

said path of the concave surface, to arrive at a delivery station of the apparatus.

Preferably, the apparatus forms part of an automated sandwich preparation plant including a slice transporter to lift the leading slice of the travelling stack from its position at the delivery station and for placing it on a conveyor carrying it to a buttering station and onward to a sandwich preparation station at which two successive buttered slices are placed in face-to-face relationship as regards their buttered faces, with sandwich filling between those buttered faces.

In order that the present invention may be more readily understood, the following description is given, merely by way of example, with reference to the accompanying drawing in which :- Figure 1 shows a sectional view taken on the line I-I of Figure 2, illustrating a stack of bread slices starting their rightward movement from an infeed end in the form of aligned adjacent slices and finishing at a delivery station where the slices are presented as a stable stack; and Figure 2 is an elevational view of the conveying apparatus, with the bread sliced omitted, viewed along the arrow 2 of Figure 1.

As shown in Figure 1, the apparatus comprises the conveyor system presenting an upwardly concave face where the downwardly moving left hand part of the conveyor system advancing individual bread slices 3 rightwardly causes those slices 3a to become realigned with a degree of shearing movement where they provide a"fanned out"configuration of the slices which continues until a delivery station where separation of the top slice 3c can be effected with any suitable means.

For example, the top slice 3c may be removed by a suction lifting mechanism, or by a spike assembly for grasping the slice 3c, or by the introduction of a separating finger between the slices 3b and 3c from the right hand side as viewed in Figure 1.

The conveyor apparatus 5 comprises an upper concave guide plate 7 and a lower convex guide plate 9 with a drive sprocket 11 at the infeed end at the left hand side of Figure 1 and a sharp nose plate 13 at the upper right hand end where the slices 3c and 3b can be seen to have been delivered. The conveying of the bread slices is effected by means of a chain conveyor 15 which is driven from the infeed end at the sprocket 11 so that the chain is pushed rightwardly along the downwardly inclined

left hand part of the upper guide plate 7 and therefore rests in contact with the upwardly facing concave face of the guide plate 7 as the conveyor reorientates from its gently downwardly inclined direction to its steeper upwardly inclined direction.

The chain may be of the same construction as a bicycle chain. For the purposes of clarity only the link rollers 17 of the chain 15 as shown in Figure 1 but the link plates 19 are partially shown in Figure 2. Figure 2 also shows side guides 14 to support the side edges of the slices 3. All panels defining the concave surface 7, the convex surface 9 and the side guides 14 are spaced from one another so as to allow any breadcrumbs to fall clear of the mechanism onto an underneath crumb tray which can be periodically emptied.

During the reorientation of the conveyor from its downwardly inclined to its upwardly inclined direction, the upper edges 21 a of the slices start out tipped slightly forwardly during the initial descent and then tend to tip back in the counterflow direction with regard to the conveyor movement, while the lower edges 21b are being driven by contact with the chains 15. This brings the upper edges 21 a into contact with one another and might even cause some compression of the upper edges 21a while simultaneously the arcuate path of the stack of slices causes a"fanned out" configuration for the slices. Achievement of this configuration involves shearing slipping between adjacent slices, helping to partially separate the upper slice 3c'from the next successive slice 3b at the delivery station.

At the delivery station the chains pass sharply round the nose of the plate 13 to begin its downward movement passing over an idler pulley 12, leaving the upper slice partially restrained by the upstanding wings 13a of the nose plate 13 and stably seated on the leading end of the stack. If desired, further vertical slots provided in the central wing 13a of the nose plate in order to permit introduction of a separator finger into the region between the separated right hand edges 21b of the upper slices 3b and 3c so as to facilitate lifting of the upper slice 3c clear of the vertically moving horizontally aligned slices at the delivery station.

Instead of the sharp nose of the plate 13, there may be a small sprocket to guide each chain for its reversal of motion, or alternatively small rollers to support the chains at that point. Since the chains are driven by the sprocket 11 at

the infeed end, any sprocket or roller at the delivery point will preferably be freely idling on a mounting shaft.

It will of course be understood that there is a sensor, in this case an optical sensor (Figure 2) comprising a transmitter 16a and a light receiver 16b between which passes a beam which becomes interrupted to indicate arrival of the leading

slice 3c at the delivery station. Thus motion of the conveyor chain 15 driven by the sprocket 11 can be intermittent and can be activated only when a top slice 3c has been removed, indicating that the next slice 3b is to take its place as a result of indexing of the conveyor chain 15.

If desired, other forms of conveyor member, for example at least one conveyor belt, may be provided in place of the chains shown in Figures 1 and 2.

Furthermore, while two such chains are shown in Figure 2, it is of course possible for more than two chains to be provided if desired.

The initial part of the path of the slices is downwardly inclined, for example at an angle of the order of 15 to the horizontal, so as to ensure that the stack of slices 3 is stable on the conveyor system when loaded at that point.

The angle of deflection of the direction of movement of the slices need not be a complete right angle, as shown. Instead a deflection of the order of 60 may suffice. The expert in the art will be able to carry out experimentation to decide on the most convenient inclinations of the chains at the in-feed end and approaching the delivery point. It is not essential for the in-feed end to be inclined downwardly but this does offer distinct advantages.

Claims

1. A method of partially separating articles in a downwardly moving stack comprising deflecting a moving stack of the articles from a first downward direction to a second upward direction, and driving the stack from that side of the stack which faces radially outwardly of the region of deflection between the first and second directions, so as to fan out the articles before arrival at a delivery station.

2. A method according to claim I wherein the stack initially moves in a gently downwardly inclined direction and ultimately moves intermittently along an inclined upward direction so as to present the leading article of the stack at a delivery station.

3. A method according to either of the preceding claims, wherein the articles are slices of food product.

4. An apparatus for partially separating articles in a moving stack, comprising a concave surface provided with a conveyor means following the path of the concave surface and able to be driven initially in a downward first direction along the surface and then reach an upward second direction after a point of deflection of the conveyor means while following said path of the concave surface to arrive at a delivery station of the apparatus.

5. An apparatus according to claim 4, wherein said conveyor means comprise conveyor chains which roll and/or slide along said concave surface.

6. An apparatus according to claim 5, and including a respective drive sprocket for each of the conveyor chains at the infeed end of said concave surface where the conveyor chain moves in said first direction, thereby advancing the conveyor chains along said concave surface causing the chain links to bunch up together to follow the arcuate surface and eventually to arrive at a point of reversal of movement of the conveyor chains where said chains are moving in said second

direction.

7. An apparatus according to claim 6, including a nose plate at said point of reversal of the chain movement, for guiding the chain links around a sharp edge of the nose plate to begin their return movement towards said sprocket.

8. An apparatus according to any one of claims 4 to 7 when forming part of a sandwich preparation plant which includes a slice transporter for lifting the leading partially separated slice of the travelling stack and for placing it onto a further conveyor for transport to a buttering station.

9. A method for at least partially separating articles in a moving stack, substantially as hereinbefore described with reference to the accompanying drawings.

10. An apparatus for at least partially separating articles from a moving stack constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.