GB2390354A

GB2390354A - Conveyor with article aligning and centring means

Info

Publication number: GB2390354A
Application number: GB0313060A
Authority: GB
Inventors: Robert Bennett; Kevin James Young
Original assignee: Ishida Europe Ltd
Current assignee: Ishida Europe Ltd
Priority date: 2002-06-06
Filing date: 2003-06-06
Publication date: 2004-01-07
Also published as: GB0313060D0; GB0212985D0

Abstract

Apparatus comprises a conveyor 10, and an article handling station which comprises a pair of gripping arms 52, 54. The gripping arms move symmetrically with respect to a line 28 parallel to the conveying direction to align an article 22 on the conveyor with the line, and centre the article on the line. An actuator controls the arms. A second pair of gripping arms may be disposed downstream of the first pair, and may also move symmetrically with respect to the line parallel with the conveying direction. The second pair of arms may be controlled by a second actuator, and arranged to operate after the first pair. A sensor 40 may be linked to the actuators, to trigger the arms when the article is sensed on the conveyor. The apparatus may include a brake assembly for stopping the article whilst it is being aligned and centred.

Description

Article Handling The present invention relates to an apparatus and method

for the handling of articles. It is mainly S concerned with articles of moderate weight (e.g. from a few hundred grams to a few kilograms) and which might be damaged by rough handling. The handling generally involves reorientation and/or transverse displacement on a conveying surface.

10 In the preparation of packaged items for sale in supermarkets, such as poultry and other meat products, a food item is commonly placed on a tray and over-wrapped in a packaging machine. The wrapped article emerges from the packaging machine and is placed on a conveying belt.

15 Conventional packaging machines tend to output articles in a fixed orientation, generally with their longest axis extending across the output conveyor. For subsequent operations, such as labelling and printing, this tends to be the wrong orientation. Furthermore the position of 20 tie article with respect to the width of the belt is crucial for correct labelling etc. Up to now, it has been necessary to reorient all the articles by hand. 'I'he present invention enables reorienting and repositioning to be automated.

Thus in a first aspect, there is provided article handling apparatus comprising a conveyor having a support surface for an article, the conveyor being operable to displace the support surface in a conveying direction; 5 and an article handling station comprising a complementary pair of gripping arms coupled to an actuator via a linkage which ensures that they move symmetrically with respect to a line parallel to the conveying direction so that they can contact an article 10 on the conveying surface on respective lateral sides whereby the article tends to be aligned with and centred on said line.

Preferably there are two pairs of complementary gripping arms movable symmetrically with respect to a 15 line parallel with the conveying direction. They may have respective actuators. The actuator for the downstream arrows may be arranged to operate after the upstream actuator. The delay will generally be small, e.g. a few milliseconds. The operation of both actuators 20 may be triggered by an article sensor e.g. employing a photocell. Preferably the article handling station includes, a brake assembly for momentarily preventing an article from being conveyed while it is aligned and centred by the 25 gripping arms. Thus a barrier may temporarily obstruct

conveying for A fraction of a second, e.g. 10-200 ms, preferably about 50ms.

There may be preliminary handling stages upstream of the gripping arms. Thus there may be a lateral abutment S adjacent one side of the conveyor for contacting an article unsymmetrically. Thus the article tends to be turned, and may also be laterally shifted away from the abutment. The abutment may be an abutment assembly. It may comprise (a) one or more abutment rollers with l0 upright axes, e.y. a pair of rollers spaced apart in the conveying direction, the downstream roller projecting farther towards the centre of the conveyor; and/or (b) an abutment surface extending generally in the conveying direction but preferably oriented to as to project IS increasingly towards the centre of the conveyor. The abutment surface may be provided by a series of upright rollers, preferably of low back pressure type.

Preferably the abutment surface follows the abutment roller(s) and is disposed so as to restrain an article 20 turned by contact with the abutment roller(s) from continuing to turn.

The conveying surface will generally be a low friction surface.

In a second aspect the invention provides a method of handling articles using apparatus according to the first aspect.

The article handling method and apparatus as 5 described above can be used to reorient and align articles such as poultry to facilitate further process steps such as weighing and/or labelling and/or packing.

An embodiment of the invention will now be described in greater detail by way of example with reference to the 10 accompanying drawing in which: Fig l is a top plan view of an article handling apparatus embodying the invention; Fig 2 is a side elevation corresponding to Fig l; and 15 Fig 3 is a front elevation as viewed at A-A in fig 1. A low-friction conveying surface lo is provided by a generally conventional conveyor belt assembly involving a belt 14 passing over a pair of rollers 16, 18, one of 20 which is driven by a motor 20. An infeed arrangement (not shown) feeds articles onto the conveying surface.

As shown, the articles are pre-wrapped chicken carcasses, on small trays. As can be seen in Fig l, an incoming chicken 22 is generally oriented with its lonyitudal axis 25 24 at right. angles to the conveying direction 26. The

chicken 22 is at one side of the conveying surface, with its neck end adjacent the edge. For further processing steps, it is desirable for it to be reoriented so its longitudinal axis 24 is parallel with the conveying 5 direction 26, and substantially aligned with the centre line 28 of the conveyor, with the neck end trailing.

As the chicken 22 moves onto the conveying surface lo, it contacts a first abutment roller 30. This is a vertically mounted, freely rotatable small roller which -

10 is adjacent the left hand edge of the conveyor (as viewed in the conveying direction). As the conveying surface tends to convey the chicken, the abutment with the roller 30 applies a turning moment. The chicken tends to turn anti-clockwise and is also shifted somewhat towards the 15 centre line 28, as is shown at 32 in Fig l. The chicken then contacts a second abutment roller 34. This is of larger diameter than the first roller 30, and positioned further inwardly of the left hand edge of the conveyor.

This urges further rotation and displacement of the 20 chicken. Immediately downstream of this second roller 34, there its an abutment wall 36 whose contact surface is provided by a series of vertical low back pressure rollers 38. The wall will generally be angled so that, in the conveying direction, it gets nearer to the centre

line 28, e.g. being at an angle of 5 degrees to it. It -

will generally be contacted by the chicken, restraining further turning of it and stabilizing it.

The arrival of a chicken is detected by a photocell S directing a beam of radiation transversely across the conveyor surface, a few centimetres above it. Data from the photocell 40 are fed to a controller 42 which provides control signals for the operation of elements to be described now. It applies suitable delays, related to 10 the speed of the conveyor. Thus it may also receive an input from the drive motor 20 of the conveyor belt.

Downstream of the wall 36, there is an array involving two pairs of gripping arms and an abutment wall. As can be seen in Fig 3, a pair of gripping arms 15 44, 96 are symmetrically mounted over the centre line 28 and linked via complementary linkages to an actuator 48.

Thus when the actuator is actuated, the arms 44, 46 are moved inwardly from the position shown in broken lines to a position at which they contact the chicken 50 20 symmetrically. The two pairs of gripping arms 44, 46 and 52, 54 are identical and are controlled by identical actuators and linkages. However, the upstream pair 52, 54 are operated a few milliseconds in advance of the downstream pair 44, 46.

Immediately downstream of the downstream pair 44, 46, there is a barrier plate 60. This is pivoted on a horizontal pivot 62. A small arm 64 fast with the plate 60 projects above the pivot 62. An actuator 66, 5 controlled by the controller 42, moves an abutment 68 into and out of a blocking position in which it obstructs the lever arm 64 and locks the plate 60 in the vertical position shown in solid lines in Fig 2.

When a chicken passes the photocell 40, after an 10 appropriate delay, the controller 42 sends a signal to the actuator 60, causing it to lock the plate 60 in the blocking position. Thus the chicken contacts it and is held there for a suitable period, e.g. 50ms. During this holding time, the two pairs of gripping arms are actuated 15 and gently grip the chicken, ensuring that it is correctly oriented and aligned. The plate is then unlocked, the arms withdraw, and the chicken can then continue to be conveyed by the conveying surface. It pushes the plate 60 out of the way, and continues to the 20 next processing station.

Claims

CLAIMS:

1. Article handling apparatus comprising a conveyor having a support surface for an article, the conveyor being operable to displace the support surface 5 in a conveying direction; and an article handling station comprising a complementary pair of gripping arms coupled to an actuator via a linkage which ensures that they are moveable symmetrically with respect to a line parallel to the conveying direction so that they can contact an 10 article on the conveying surface on respective lateral sides whereby the article tends to be aligned with and centred on said line.

2. Apparatus according to claim 1 including a 15 second pair of complementary gripping arms downstream of the first pair and coupled to an actuator via a linkage which ensures that they are movable symmetrically with respect to the line parallel with the conveying direction.

3. Apparatus according to claim 2 wherein said two pairs of arms have respective actuators, and the actuator for the downstream arms is arranged to operate after the upstream actuator.

4. Apparatus according to any preceding claim including an article sensor for sensing an article on the conveyor, the sensor being linked to the or each said actuator to trigger its operation.

5. Apparatus according to any preceding claim wherein the article handling station includes a brake assembly for momentarily preventing an article from being conveyed while it is aligned and centred by the gripping 10 arms.

6. Apparatus according to any preceding claim further including a preliminary handling stage upstream of the gripping arms, comprising a lateral abutment 15 adjacent one side of the conveyor for contacting an article unsymmetrically, whereby in use an article tends to be turned, and may also be laterally shifted away from the abutment.

20

7. Apparatus according to claim 6 wherein the abutment comprises (a) one or more abutment rollers with upright axes and/or (b) an abutment surface extending generally in the conveying direction but oriented to as to project increasingly towards the centre of the 25 conveyor.

8. Apparatus according to claim 7 including a said abutment surface which follows said one or more abutment roller(s) and is disposed so as to restrain an article 5 turned by contact with the abutment roller(s) from continuing to turn.

9. Article handling apparatus substantially as herein described with reference to and as illustrated in 10 the accompanying drawings.

10. A method of handling articles using apparatus according to any preceding claim, wherein articles are conveyed by the conveyor through the article handling 15 station.