GB2397285A

GB2397285A - Gate for use in packaging/stacking

Info

Publication number: GB2397285A
Application number: GB0301275A
Authority: GB
Inventors: Frank Groom
Original assignee: Jacob White
Current assignee: Jacob White
Priority date: 2003-01-20
Filing date: 2003-01-20
Publication date: 2004-07-21
Also published as: GB0301275D0

Abstract

A shutter transfer system includes two blades 2 which are moveable between a first position in which opposing edge portions of the blades are closely spaced to a second position in which opposing edges of the blade are separated. The blades are moveable between the first and second positions by linear movement in horizontal, parallel, mutually opposite directions. This allows an article item 15 to sit on the blades and fall through the gap in blades without tilting or twisting. A succession of such systems may be provided one above another so that a stack may be formed, Figure 1. The blades 2 may be moved by a servo motor via a pinion 12 and racks 13, 14. Vertical guide plates (6) on the blades 2 may position items thereon.

Description

1 2397285

SHUTTER TRANSFER SYSTEM AND METHOD

This invention relates to a shutter transfer system and a method of transferring an article using a shutter transfer system. In particular, this application relates to a shutter transfer system for use in a packaging apparatus for transferring an article e.g. from the production line to a cantoning machine.

It is known to provide a shutter transfer system for use in a packaging apparatus. The known shutter transfer systems include at least one shutter having two blades. The blades are connected to and are moved by a pneumatic control system. In use, an article is deposited and supported on the blades until the blades are moved in such a manner so as to allow the product to fall through the blades either into a packaging machine or onto a further shutter.

In one known system, the blades are angled downwards and opposing edges of the blades do not touch but, instead, are separated by a gap that is smaller than the size of the product. In this way, the article can be supported by the blades without falling through the gap. When it is desired to transfer the article either into a packaging machine or onto a further shutter, the blades are moved away from each other in a curved trajectory to increase the size of the gap and thus allow the article to fall therethrough.

The problem with this arrangement is that because the blades do not present a support surface for the article to rest on, if the article is not carefully positioned onto the shutter blades, it may not be supported squarely by the blades but may tip or tilt with part of the article protruding through the gap between opposing edges of the blades. Therefore this arrangement results in little control over the orientation of the article. This, in turn, makes it very difficult to collate articles i.e. stack articles one upon another on a shutter. Collation of articles is desirable when more than one article is to be packaged in a single packaging.

An alternative known arrangement provides a shutter having blades with partially abutting edges, the blades providing a horizontal support surface on which an article can sit. In order to allow the article to fall between the blades, the blades are moved in a pivoting, scissor-type action such that one end of the opposing edges moves apart whilst the other stays in abutment.

The problem with this arrangement is that the article tends to "nosedive" into the gap as a result of the fact that the gap created by movement of the blades is larger at one end than the other. Thus the article may not fall squarely through the gap i.e. there is a lack of orientation control of the article as it falls through the gap.

It is desirable to produce a shutter transfer system that allows for accurate control over the orientation of an article as it falls through the shutter. This facilitates collation of articles.

Accordingly, in a first aspect, there is provided a shutter transfer system comprising at least one shutter, said at least one shutter including two blades which are moveable between a first position in which opposing edge portions of the blades are closely spaced to provide a support surface for supporting an article, to a second position in which opposing edge portions of the blade are separated such that an article can fall from the support through the shutter, characterized in that said blades are moveable between the first and second positions by linear movement in horizontal, parallel, mutually opposite directions.

In a second aspect, there is provided a method of transferring an article, said method comprising depositing an article on a shutter, said shutter comprising two blades in a first position in which opposing edge portions of the blades are closely spaced to provide a support surface for the article; and moving the blades to a second position in which opposing edge portions of the blades are separated, thus allowing the article to fall through the shutter, characterized in that the blades are moved in horizontal, parallel, mutually opposite directions.

In such a system and method, the orientation of the product can be accurately controlled because the article will sit squarely on the blades when they are closely spaced in the first position and then will fall through the gap squarely as the blades move apart to the second position because the gap between the opposing edge portions is created at an equal rate along the opposing edge portions.

Preferably, in the first position, the opposing edge portions of the blades are in abutment.

Preferably, in the second position, opposing edge portions of the blades are equidistant from each other at all points along the opposing edges. This results in a gap that is of a uniform width in the second position which prevents "nose-diving" of the article as in the

prior art.

Preferably, the blades are connected to and are moveable between the first and second positions by a servo motor. Such a motor provides accurate control over the movement of the blades and allows for faster and quieter operation then the pneumatic systems that have been used previously.

The servo motor may be any commercially available servo motor. The preferred motor is a Panasonic 400_ which is preferred because of its small size.

The blades are preferably coplanar and preferably substantially horizontal. The blades may be made of any material but are preferably made of stainless steel. In preferred embodiments, the blades are strengthened using support rods which extend on the underside of the blade to prevent twisting or bending of the blades when a heavy article is positioned on the shutter. There is also provided, in preferred embodiments, linear bearings to ensure that the blades move in a linear motion.

The opposing edges preferably have a linear profile but they may have any profile, for example wavy or castellated.

Preferably, each blade is connected to a respective toothed rack, the teeth of both racks being in meshed contact with a toothed pinion gear. The pinion gear is linked to the servo motor such that the pinion gear can be rotated by the servo motor, rotation of the pinion gear resulting in linear motion of the two racks and blades. The pinion gear is preferably linked to the servo motor by a drive pulley system. The system preferably includes a first drive wheel which is rotatable by the servo motor axel and a second drive wheel connected to the pinion gear by a drive shaft. A drive belt is looped around the first and second drive wheel for transferring motion of the first drive wheel to the second drive wheel and hence to the pinion gear.

Preferably each toothed rack is connected to its respective blade by bracket which, preferably, extends substantially horizontally from the rack.

The degree of rotation of the pinion gear determines the width of the gap that is opened up between the opposing edge portions of the blades in the second position. Thus the width can be varied so as to allow various size articles to fall through the gap.

Preferably, the transfer system includes detection means for detecting an article located on the support surface. This allows for triggering of the movement of the blades into the second position to allow the article to fall through the shutter. The detection means may be any sensor and may be, for example, a light emitter and light receiver, the light path being obscured by the article when the article is in position on the support surface.

Preferably, the system further includes guide plates which extend substantially perpendicularly from the blades for guiding the article into the correct position on the shutter. In the correct position, the article will be positioned substantially symmetrically over the line of abutment of the two opposing edge portions of the blades. This will ensure that the article does not tilt or twist as the blades are moved to the second position. The distance between the guide plate on one blade and the guide plate on the other blade of the shutter is variable e.g. manually to ensure that products of various sizes can be accommodated.

This variability is achieved by mounting the plates on sliding mounts.

The guide plates are independent of the shutter blades and do not move as the shutter opens.

Preferably, the shutter transfer system comprises more than one shutter, each shutter having two blades.

In most preferred embodiments, there are three shutters but there could be more than three shutters in some S systems. Preferably, all of the shutters have the same structure. The shutters are preferably vertically aligned.

In a three shutter system, the first shutter acts as a receiving shutter, the second as a collating shutter and the third as a timing shutter. The first shutter will receive an article from a product delivery means e.g. a conveyor from a production line. The second shutter will receive articles from the first shutter and, if desired, these articles can be collated i.e. piled one on top of another on the second shutter.

To achieve this, the first shutter would repeatedly open delivering successive articles whilst the second shutter remains in the first position with blades closely spaced. When the required number of articles have been stacked upon each other, the second shutter will open and the collated articles will fall through onto the third shutter. This shutter will remain in the first position with closed blades until a packaging article e.g. a carton is located below the third shutter on packaging delivery means e.g. a conveyor in a cantoning machine. This the third shutter is a timing shutter and only opens at the point when packaging is positioned below the third shutter.

In a third aspect there is provided a packaging apparatus comprising article delivery means, packaging delivery means and a shutter transfer system according the first aspect of the present invention, the shutter transfer system being positioned between said article delivery means and said packaging delivery means for transferring an article from said article delivery means to said packaging delivery means.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure l is a perspective view of a preferred shutter transfer system; Figure 2 is an exploded view of the preferred means for achieving blade movement; Figure 3 is a schematic view showing the method of blade movement; and Figure 4 shows an exploded rear perspective view of the preferred shutter transfer system.

Figure 1 shows a shutter transfer system having three shutters. The first shutter 1 comprises two blades 2 that have opposing edges 3 which are in abutment, the blades providing a support surface for an article. The opposing edges have a linear profile. The blades are co-planar and are substantially horizontal.

They are approximately 57 cm by 21 cm and are made of stainless steel. The blades are connected to and moveable by a servo motor 1 which is a Panasonic 400_ motor.

The system also includes guide means 6 which are plates upstanding vertically from the blades. These guide plates are approximately 42 cm long and 12 cm high and made of stainless steel. They are positioned to ensure that any article sitting on the blades when they are in abutment sits symmetrically over the line of abutment of the opposing edges 3 of the blades 2. The plates are mounted on a sliding mount to allow the distance between the plates to be varied manually to accommodate various sizes of articles. The plates have an aperture which is aligned with a sensor 7. This sensor is for detecting when there is an article located on the support surface and is in communication with a programmable logic controller (PLC) which controls movement of the blades by communication with the servo motor. The sensor emits a light beam which passes the apertures in the guide plates to an aligned receiver.

If an article is positioned on the blades, the light beam is blocked and not received by the receiver. Thus the sensor can detect the presence of the article.

The second and third shutters 17,18 are of identical structure to the first shutter.

Figure 2 is an exploded view of the elements used to achieve movement of the blades between the first and second positions.

The servo motor 4 has an axel 8 which is connected to a first drive wheel 9. Rotation of the axel 8 by the motor 4 results in rotation of the first drive wheel 9.

Any rotation of the first drive wheel 9 is transferred to a second drive wheel 10 by a toothed belt 5. The second drive wheel 10 is connected to a drive shaft 11.

The drive shaft 11 is connected to a toothed pinion gear 12. It will therefore be appreciated that rotation of the servo motor is ultimately transferred to the pinion gear via the axel 8, drive wheels 9, 10 and drive shaft 11.

The pinion gear 12 has teeth which are in meshed contact with teeth on two teethed racks 13,14. These racks are vertically aligned with one rack 12 positioned below the pinion gear and one rack 14 positioned above the pinion gear. One rack is connected via a bracket to one of the blades whilst the other rack is connected by a bracket to the other blade. Rotation of the pinion gear will result in linear, parallel motion of the racks and blades either away or towards each other as shown in Figure 3.

Figure 3 shows a schematic view of the racks, l0 blades and pinion gear. The teeth on the gear and racks are not shown. It can be seen that, as the pinion gear is rotated clockwise, the racks and blades move in parallel but opposite directions thus creating a gap between the opposing edges of the blades. The width of the gap can be varied by varying the degree of rotation of the pinion gear so that the gap is sufficient to allow the article 15 to fall through the gap.

For clarity reasons, Figure 3 shows the blades positioned vertically above the racks but is not the case in preferred embodiments. Preferably, the brackets 16 and blades 2 extend horizontally away from the racks 13,14 as shown in Figure 4.

In Figure 4, it an be seen that, in order to allow the blades 2 to be coplanar and horizontal, brackets have to be used which compensate for the fact that the toothed racks are vertically aligned one on top of the other. The brackets are both L-shaped brackets but the bracket connected to the upper rack 14 extends downwards and then out horizontally from the rack whilst the bracket connected to the lower rack 13 extends upwards and then out horizontally from the rack.

In use, initially all of the shutters in the system will be shut with the blades in abutment. An article is delivered to the first shutter 1, for example by a conveyor of a production line and the guide means 6 ensure that the article is correctly positioned i.e. positioned substantially symmetrically over the line of abutment of the opposing edges of the blades. The sensor 7 detects that an article is positioned on the blades and sends a signal to the PLC which then sends a signal to the servo motor. The servo motor then moves the blades to the second, open position by way of the axel 8, drive wheels 9, 10, drive shaft 11, pinion gear 12 and racks 13,14.

In the second position, the gap is sufficient to allow the article to fall through the shutter onto the second shutter 17. This second shutter has the same structure as the first shutter and the same elements for use in moving the blades between the first and second positions. If collation of products is required, then the second shutter is retained with the blades in the first position i.e. with abutment of opposing edges whilst the first shutter l receives and delivers to the second shutter multiple articles. The second shutter will support multiple articles stacked one on top of another, the guide plates of the second shutter ensuring that the stack is orderly.

When the stack is made up of the desired number of articles, the blades of the second shutter are moved the second position so that the stack can fall through onto the third shutter 18 which also has an identical structure as the first shutter. This third shutter is the timing shutter which will support the collated articles and open at a time when a packaging article is located below the third shutter e.g. on a conveyor of a cantoning machine.

In some cases, it will not be desirable or necessary to collate the products and, in this case, only a single item will be passed from the second shutter to the third shutter and into the carton.

The embodiment described above is by way of example only and various modifications will be readily apparent to those skilled in the art.

Claims

A shutter transfer system comprising at least one shutter, said at least one shutter including two blades which are moveable between a first position in which opposing edge portions of the blades are closely spaced to provide a support surface for supporting an article, to a second position in which opposing edge portions of the blades are separated such that an article can fall from the support surface between the blades, characterized in that in said blades are moveable between the first and second positions by linear movement in horizontal parallel, mutually opposite directions.
2. A shutter transfer system according to claim l wherein, in the second position, opposing edge portions of the blades are equidistant from each other at all points along the opposing edge portions.
3. A shutter transfer system according to claim l or claim 2 wherein, in the first position, opposing edge portions of the blades are in abutment.
4. A shutter transfer system according to any one of claims 1 to 3, wherein said blades are connected to and are moveable between the first and second positions by a servo motor.
5. A shutter transfer system according to claim 4, wherein each blade is connected to a respective toothed rack, the teeth of both racks being in meshed contact with a toothed pinion gear, the pinion gear being linked to the servo motor such that the pinion gear is rotatable by said servo motor, rotation of the pinion gear resulting in linear motion of the toothed racks and blades.
6. A shutter transfer system according to claim 5, wherein said pinion gear is linked to said servo motor by a drive pulley system, said system including a first drive wheel which is rotatable by the servo motor axel, a second drive wheel connected to the pinion gear by a drive shaft and a drive belt that is looped around the first and second drive wheel for transferring motion from said first drive wheel to said second drive wheel.
7. A shutter transfer system according to any one of the preceding claims, further including detection means for detecting an article located on said support surface.
8. A shutter transfer system according to any one of the preceding claims, further including guide plates extending substantially perpendicularly from said blades for positioning an article on said support surface.
9. A shutter transfer system according to any one of the preceding claims, comprising three shutters, the shutters being vertically aligned.
10. A packaging apparatus comprising article delivery means, packaging delivery means and a shutter transfer system according to any one of the preceding claims, the shutter transfer system being positioned between said article delivery means and said packaging delivery means for transferring an article from said article delivery means to said packaging delivery means.
11. A method of transferring an article, said method comprising depositing an article on a shutter, said shutter comprising two blades in a first position in which opposing edge portions of the blades are closely spaced to provide a support surface for said article; and moving the blades to a second position in which opposing edge portions of the blade are separated, thus allowing the product to fall from the support surface through the shutter, characterized in that the blades are moved in mutually opposite, parallel, horizontal directions.
12. A method according to claim 11 wherein the step of moving the blades includes moving the blades such that, in the second position, opposing edge portions of the Is blades are equidistant from each other at all points along the opposing edges.
13. A method according to claim 11 or claim 12 wherein, the step of depositing an article includes depositing the article on the shutter with the two blades in a first position in which opposing edge portions of the blades are in abutment.
14. A method according to any one of claims 11 to 13, wherein the step of moving the blades is achieved using a servo motor.
15. A method according to claim 14, wherein the step of moving the blade comprises rotating a toothed pinion gear which is linked to the servo motor, the toothed pinion gear being in meshed contact with two toothed racks, each of which is connected to one of the blades such that the rotation of the pinion gear results in linear motion of the toothed racks and blades.
16. A method according to claim 15 wherein said step of rotating the toothed pinion gear comprises rotating a first drive wheel by the servo motor axel, transferring the motion of the first drive wheel to a second drive wheel using a drive belt, the second drive wheel having a drive shaft connected to the toothed pinion wheel.
17. A method according to any one of claims 11 to 16 further including the step of detecting an article located on the support surface.
18. A method according to any one of claims 11 17 further including guiding the article to a correct position on the support surface.
19. A method according to any one of claims 11 to 18 further including allowing the article to fall through the shutter onto a second shutter comprising two blades in a first position in which opposing edge portions of the blades are closely spaced; and moving the second shutter blades to a second position in which opposing edge portions of the second shutter blades are separated, thus allowing the article to fall through the second shutter.
20. A method according to claim 19 further including allowing the article to fall through the second shutter onto a third shutter comprising two blades in a first position in which opposing edge portions of the blades are closely spaced; and moving the third shutter blades to a second position in which opposing edge portions of the third shutter blades are separated, thus allowing the article to fall through the third shutter.
21. A shutter transfer system substantially as any one embodiment herein described with reference to the accompanying figures.
22. A method of transferring an article substantially as any one embodiment herein described with reference to the accompanying figures.