GB2575919A

GB2575919A - Bag placing apparatus

Info

Publication number: GB2575919A
Application number: GB1909206.3A
Authority: GB
Inventors: Rees Edward; Rees Thomas
Original assignee: Rees Machinery Group Ltd
Current assignee: Rees Machinery Group Ltd
Priority date: 2018-06-26
Filing date: 2019-06-26
Publication date: 2020-01-29
Anticipated expiration: 2039-06-26
Also published as: GB201810425D0; GB201909206D0; GB2575919B

Abstract

A bag placing apparatus for a packaging machine comprising a conveyor, a rotary carriage, and a profiler assembly. The conveyer 10 comprises a set of parallel bars 18 moving along a generally rectangular rotary path, a pair of laterally spaced apart guide rails, and a plurality of paddle members 20 slidable along the bars, each paddle member having a guide engaging member. The rotary carriage is mounted within the conveyor and comprises a pair of elongate hubs 106 parallel and spaced apart from each other with a first open-topped crate 102 pivotably mounted between the hubs at one end and a second open-topped crate pivotably mounted between the hubs at the other end. The rotary carriage comprises a gear arrangement configured such that the rotary path of the ends of the hubs include straight sections and the first and second open-topped crates remain substantially upright during a full rotation of the hubs. The profiler assembly comprises a flexible contact member mounted on a support assembly 202. The support assembly is configured to move the flexible contact pad between a convex configuration and a flat configuration within the first or second open-topped crate.

Description

BAG PLACING APPARATUS

Field of the Invention

This invention relates generally to a bag placing apparatus for use in a method of automated or semi-automated packaging of free flowing material.

Background of the Invention

There are many different fields and applications in which it is necessary to package defined quantities of loose free-flowing materials for onward transport and delivery. Such loose or free-flowing materials range from particulate foodstuffs, such as flour, salt, dog food or grains, to heavy duty materials used in construction and similar fields, such as aggregate or sand, and the present invention is not necessarily intended to be in anyway limited in this regard.

Various types of packaging apparatus exist for the purpose of packaging defined quantities or weights of these types of materials. In some types of such packaging plants, the material is dispensed from a hopper, and predefined quantities thereof are weighed out, transported to a packaging area and then wrapped in film dispensed from a large reel. Each package, thus produced, is then moved out of the packaging apparatus for storage and onward handling.

However, there is an increasing preference for using pre-made bags to package the materials, rather than the film wrapping described briefly above. This is because the use of pre-made bags significantly increases the flexibility of the packaging plant, allowing different bag sizes and types to be used without significant alteration to the apparatus, thereby allowing different customers’ varying requirements to be accommodated without significant additional effort or cost.

Bagging plants are known, which use bagging apparatus for packaging defined quantities of loose material using pre-made bags. In all such bagging apparatus, there will be a number of key steps performed, namely picking up a single bag and depositing it on a conveyor, transporting the bag to a filling station, opening, filling and closing the bag, and transporting the filled bag to an exit location of the apparatus. The present invention is specifically concerned with the first two of the above-mentioned steps, namely repeatedly picking up a single bag from a stack of pre-made bags (each having an open end), depositing the bag on a conveyor and transporting the bag to the filling station. These steps may collectively be termed “bag placing”.

Starting with the first step in a bag placing process, suction devices have typically been used in known apparatus to repeatedly pick up the topmost bag of a stack of bags. The suction device may be mounted on a moving arm or rail, such that, once a bag has been picked up, it can be moved to a conveyor, before returning the suction device to the start position, ready to pick up the next topmost bag in a stack. In alternative arrangements, the suction device may simply move up and down relative to the stack of bags with a rolling (intermittent) conveyor moving in the space between the suction device and the top of the stack of bags. In this case, the conveyor stops when a gap therein is aligned with the suction device, allowing the suction device to move down, pick up the topmost bag of the stack below and move back up (with the bag); the conveyor then moves, until a receiving surface thereof is beneath the suction device and bag, and the suction device then releases the bag onto the receiving surface. The conveyor moves (transporting the bag to the adjacent filling station) and stops at the next gap so the process can be repeated for the next topmost bag in the stack.

There are a number of issues associated with this conventional bag placing process. Firstly, the issue of reliably separating the topmost bag from the stack has long posed a significant problem in an automated bag placing process. Depending on the type and construction of the pre-made bags, they may be welded together, or static build-up between the bags may hold them together, such that when the suction device picks up the topmost bag in a stack, the next one down remains attached to it and two (or more) bags are picked up at the same time. This, in turn, will cause the bagging apparatus to malfunction at the filling station, requiring human intervention. Of course, the problem can, in theory, be overcome by using a stronger suction device, designed to counteract the potential attractive forces between the bags in a stack. However, this does not circumvent an additional potential problem associated with pre-made bags that have side seams and, sometimes, even side pleats, making the sides (and possibly the closed end) thicker than the rest of the bag. This, in turn, causes a stack of such bags to ‘sag’ in the middle, such that a concave top surface is presented to the suction device. The larger the stack, the more pronounced will be the concave surface. Clearly, in order to work effectively, the topmost bag needs to be as flat as possible and the more pronounced any concave region thereof is, the less effective will be the suction effect, resulting in a significantly increased likelihood that two or more bags will be picked up simultaneously. The only way that this problem can be minimised (but not solved) in prior art arrangements, is to present relatively small stacks of bags at a time to the pick-up location. Since the placing of a stack of bags for this purpose is almost solely performed manually in prior art bagging plants, this is clearly highly inefficient and requires at least one person to be present at all times, repeatedly placing small stacks of bags onto the bagging apparatus and ensuring that single bags are correctly picked up at the start of each cycle.

Attempts have been made to solve the above-described problem of bag separation by providing a mechanism for this purpose. For example, LIS2018050874 describes an apparatus and method for repeatedly separating and displacing a topmost bag of a stack of bags, which comprises a vacuum gripper and a stack engaging arm that work in unison to repeatedly separate and displace each bag in a stack. The vacuum gripper first engages and lifts an end portion of the topmost bag in the stack, and the stack engaging arm then moves into the space between that end portion and the end portion of the next bag down and engages the stack at that location (to hold all the bags in place), whilst the topmost bag is removed completely from the stack and conveyed to the filling station. The stack engaging arm then moves back and the process is repeated for the next topmost bag in the stack.

However, this arrangement does not adequately address the problems outlined above. Firstly, whilst the static build-up will, of course, be less at the end portions of the stack, if two bags have been welded together during the manufacturing process, the vacuum gripper will still pick them both up and the stack engaging arm cannot act to separate them. This problem is exacerbated by the use of the vacuum gripper at an edge of the bags, where the surface presented thereto is still not uniform due to the seam/pleat. Furthermore, the described arrangement is limited in terms of the size of each stack of bags, by the space allocated between the stack receiving surface and the uppermost operable position of the stack engaging arm, thus limiting the flexibility of the bagging apparatus, not just in terms of the types of bags that can be used, but also the quantities in which the bags need to be filled, and significant manual input is still required to keep refilling the bag pick-up station.

Another significant problem that remains inadequately addressed in prior art bagging apparatus is that of correct bag alignment as it is presented to the filling station. Current automated filling stations are highly efficient and effective, provided each bag is fed thereto, from the bag pick-up station, in perfect alignment (i.e. with the open end facing the filling station and perfectly transverse to the direction of travel). If, when the bag is placed by the pick-up apparatus onto the conveyor to the filling station, it is mis-aligned in some way (for example, due to an external force such as wind), the apparatus will malfunction at the filling station, requiring human intervention and machine down time. Different types of guide and rail systems have been proposed to try and circumvent this problem, but not only do such arrangements significantly increase the number of components and moving parts in the apparatus, thereby increasing the cost, likelihood of failure, maintenance burden and, arguably more importantly, the footprint of the apparatus, but it also introduces its own point of potential failure, because a mis-aligned bag can be mis-fed and trapped underneath guide components, causing the machine to malfunction and therefore require human intervention and inevitable down time.

It is an object of various aspects of the present invention to address at least some of these issues and provide a bag placing apparatus wherein bags are repeatedly and reliably picked up, one by one, and reliably presented to the filling station, correctly aligned and oriented, whilst enabling the footprint of the apparatus (i.e. the physical space it occupies) to be minimised to the extent that, at least in some exemplary embodiments, it can be housed within an arctic or shipping container to provide a highly effective and efficient mobile bagging solution.

Summary of the Invention

In a first aspect of the invention, there is provided a bag placing apparatus for a packing machine for packaging free-flowing material in pre-made bags, the bag placing apparatus comprising:

a conveyer comprising:

a rotating platform having a generally rectangular rotary path, in use, about a first axis;

a set of parallel bars mounted on said rotating platform, said bars extending substantially parallel to said first axis and forming a generally planar receiving surface;

a pair of laterally spaced apart guide rails located along an edge of said rectangular rotary path and extending in the direction of travel of said rotating platform, each guide rail having at least an first profile and a second profile along its length, and wherein the lateral space between the guide rails at said first profile is greater than that at said second profile; and a plurality of paddle members mounted at longitudinally spaced apart locations on said receiving surface, each paddle member having a body portion and a guide engaging member and being slidably mounted on a respective bar via an aperture in said body portion thereof, said guide engaging member being coupled at a first end to said body portion and configured to engage a respective guide rail, in use, for movement therealong; and a rotary carriage mounted within the conveyor, the rotary carriage comprising:

a pair of elongate hubs, each hub being rotationally mounted on a respective shaft via a respective sun gear such that the hubs are substantially parallel to, and spaced apart from, each other;

a first open-topped crate pivotally mounted between the hubs at one end and a second open-topped crate pivotally mounted between the hubs at its other end, the first open-topped crate being coupled to each hub via a respective first gear wheel and the second open-topped crate being coupled to each hub via a respective second gearwheel;

each hub carrying a first link arm and gear wheel arrangement mechanically coupled between the respective sun gear and first gear wheel and a second link arm and gear arrangement mechanically coupled between the respective sun gear and the respective second gear wheel, the first and second link arm and gear wheel arrangements being arranged and configured such that the rotary path of the hubs, at their ends, is substantially rectangular and the first and second opentopped crates remain substantially upright throughout a full rotation of the hubs; and a profiler assembly, said profiler assembly comprising:

at least one profiler member comprising a flexible contact member having an outward, operational surface and being mounted on a support assembly, the support assembly being configured, in use, to exert a force on the flexible contact pad so as to urge said operational surface of said flexible contact pad against the bottom of a pile of pre-made bags contained within the first or second open-topped crate at an operation position during a bag placing operation, the flexible contact pad being gradually movable from a first configuration, in which the flexible contact pad presents a convex operational surface, and a second configuration in which said operational surface is substantially flat, the profiler assembly further comprising a control device configured, in use, to cause movement of said flexible contact pad from said first configuration to said second configuration as said pile of bags is depleted during said bag placing process.

The axis of rotation of the rotary carriage can be substantially perpendicular to the first axis of the conveyor (or put another way, substantially parallel to the direction of travel of the rotating platform).

The conveyor can further comprise a pair of chain belts that define the generally rectangular rotary path of the rotating platform, wherein the set of parallel bars is mounted between the pair of chain belts.

The rotary carriage can be mounted within the conveyer defined by the pair of chain belts. The centre of each hub can be located between the pair of chain belts.

The first and second open-topped crates can be arranged such that they follow the same substantially rectangular rotary path as the ends of the hubs and are 180° out of phase with each other. The conveyor and the rotary carriage can be dimensioned and arranged such that such that when the bag placing apparatus is orientated for use, the upper edge of the rotary path of the first and second open-topped crates passes horizontally beneath the upper edge of the rectangular rotary path of the rotating platform

The conveyor and the rotary carriage can be dimensioned and arranged such that when the bag placing apparatus is orientated for use, the first and second opentopped crates are movable in turn to the operating position corresponding to a position directly below a bag receiving region of the conveyor, the bag receiving region corresponding to the upper edge of the rectangular rotary path of the rotating platform. When the first or second open-topped crate is at the operating position, it can be located at an upper corner of its rotary path, and the other of the first and second open-topped crates can be located at a lower corner of its rotary path, diagonally opposite the first or second open-topped crate at the operating position.

The profiler assembly can be mounted for vertical movement relative to the bag placing apparatus (relative to the conveyor and/or rotary carriage) when orientated for use.

Each of the first and second open-topped crates can comprise a base with a slot or gap for allowing the flexible contact pad of the profiler assembly to extend therethrough.

The profiler assembly can be positioned relative to the rotary carriage such that when one of the first and second open-topped crates is at the operating position, the profiler assembly is moveable to extend the flexible contact pad through the slot or gap in the base of said one of the first and second open-topped crates at the operating position.

The bag placing apparatus can further comprise a distance measuring sensor configured to detect the height of a stack of bags contained within the first or second open-topped crate when at the operating position.

The control device of the profiler assembly can be configured to control the vertical position of the flexible contact pad relative to the first or second open-topped crate when at the operating position based on a signal received from the distance measuring sensor (indicating the height of the stack of bags). The vertical position can be controlled such that the top of a stack of bags contained within the first or second open-topped crate at the operating position remains a constant vertical distance from bag receiving region of the conveyer.

The distance measuring sensor can be configured to detect a difference in the height between the centre of a stack of bags and the edges of a stack of bags contained within the first or second open-topped crate at the operating position.

The control device of the profiler assembly can be configured to move the flexible contact pad between its first configuration and its second configuration based on a signal received from the distance measuring sensor (indicating the difference in height between the centre of a stack of bags and the edges of a stack of bags).

The rotary carriage can be configured to move the first or second open-topped crate to the operating position when the distance measuring sensor detects that the first or second open-topped crate currently at the operating position is empty; and the rotary carriage can be configured to remain stationary when the distance measuring sensor detects that the first or second open-topped crate at the operating position is not empty.

The conveyor can comprise a plurality of sets of parallel bars to form a plurality of generally planar receiving surfaces, each set of parallel bars being separated by a space.

The bag placing apparatus can further comprise a vacuum sucker configured to pick up the topmost bag from a stack of bags contained in the first or second opentopped crate at the operating position and place the topmost bag on to the, or one of the, generally planar receiving surfaces of the conveyor as it travels along its rotary path.

In accordance with a second aspect of the present invention, there is provided a conveyor for use in the bag placing apparatus according to the first aspect, the conveyor comprising:

- a rotating platform having a generally rectangular rotary path, in use, about a first axis;

- a set of parallel bars mounted on said rotating platform, said bars extending substantially parallel to said first axis and forming a generally planar receiving surface;

- a pair of laterally spaced apart guide rails located along an edge of said rectangular rotary path and extending in the direction of travel of said rotating platform, each guide rail having at least an first profile and a second profile along its length, and wherein the lateral space between the guide rails at said first profile is greater than that at said second profile; and

- a plurality of paddle members mounted at longitudinally spaced apart locations on said receiving surface, each paddle member having a body portion and a guide engaging member and being slidably mounted on a respective bar via an aperture in said body portion thereof, said guide engaging member being coupled at a first end to said body portion and configured to engage a respective guide rail, in use, for movement therealong.

The conveyor can comprise a pair of chain belts. Each chain belt can be mounted around a set of rollers. Each set of rollers can comprise four roller members arranged in a generally rectangular formation. Each chain belt can be a closed-loop. Each chain belt can be looped around the four roller members in each set such that each chain belt is in a generally rectangular formation, with each roller member located at a respective inner corner of each loop. Each chain belt can comprise a plurality of link members, wherein the link members are articulated. Each link member can comprise a main body having a pair of apertures being substantially perpendicular to the direction of travel of the chain belt, when in use. The set of parallel bars can be mounted between the chain belts. Each parallel bar can extend through a respective aperture in a respective link member.

The conveyor can comprise a plurality of sets of parallel bars, each set forming a generally planar receiving surface. The sets of parallel bars can be separated from each other by a space. The sets of parallel bars can be substantially equally spaced apart.

Each paddle can be mounted on a pair of bars. The body portion of each paddle can have a generally L-shaped cross-section. The body portion can comprise a first plate-like portion defining the aperture in the body portion. The body portion can further comprise a second plate-like portion that is substantially perpendicular to the first plate-like portion. The first plate-like portion can lie substantially parallel to the receiving surface and the second plate-like portion can be substantially perpendicular to the receiving surface.

The plurality of paddles can be arranged in pairs. Each paddle within each pair can be mounted on the same bar or pair of bars. Each pair of paddles can be mounted such that one of the paddles of a pair is nearer one of the chain belts and the other paddle of the pair is nearer the other chain belt, such that a path is defined between each pair of paddles. The principle planes of the second plate-like portion of the paddles within each pair of paddles can be substantially parallel to, and facing, each other.

The guide engaging member of each paddle member can comprise an elongate pin. The pin can extend orthogonally and generally centrally from the “bottom” of the first plate-like portion (i.e. from the side opposite to the receiving surface).

Each guide rail can comprise a first section having the first profile and a second section having the second profile. The first sections of the guide rails can taper inwardly toward each other and the second sections can be substantially parallel to each other (and the direction of travel of the rotating platform). A wear strip for reducing friction and wear can be provided along each guide rail on a surface that engages the guide engaging member.

The conveyor can comprise drive means configured to drive the chain belts around the rollers. The drive means can be configured to continuously drive the chain belts around the rollers in a single direction.

In accordance with a third aspect of the present invention, there is provided a profiler assembly for use in the bag placing apparatus according to the first aspect, said profiler assembly comprising at least one profiler member comprising a flexible contact member having an outward, operational surface and being mounted on a support assembly, the support assembly being configured, in use, to exert a force on the flexible contact pad so as to urge said operational surface of said flexible contact pad against the bottom of a pile of pre-made bags during a bag placing process, the flexible contact pad being gradually movable from a first configuration, in which the flexible contact pad presents a convex operational surface, and a second configuration in which said operational surface is substantially flat, the profiler assembly further comprising a control device configured, in use, to cause movement of said flexible contact pad from said first configuration to said second configuration as said pile of bags is depleted during said bag placing process.

The profiler assembly can comprise a plurality of flexible contact pads, e.g. three flexible contact pads. Each flexible contact pad can be arranged in a side-by-side, spaced apart relation. Each flexible contact pad can be mounted on a pair of arms. Each arm in each pair of arms can be pivotally mounted at a first end to the lower surface of a respective flexible contact pad (relative to the profiler assembly, when it is oriented for use). The pivotal couplings between each pair of arms and the respective flexible contact pad can be longitudinally aligned and substantially equally spaced from the centre of the flexible contact pad. The second end (opposite to the first end) of each arm in each pair of arms can be pivotally coupled to a generally Yshaped hub. The arms in each pair of arms can be angled toward each other (from the first end to the second end). The profiler assembly can further comprise a lever arm coupled at one end to each Y-shaped hub. Each lever arm can be substantially parallel to the longitudinal axis of a respective flexible contact pad. The lever arms can be arranged in parallel, transversely aligned and spaced apart relation. The opposing end of each lever arm can be rotationally coupled to a common shaft that extends orthogonally to the longitudinal axis of the lever arms and the flexible contact pads. The profiler assembly can further comprise a pneumatic cylinder mounted between at least one of the Y-shaped hubs and the (centre of the) lower surface of a respective flexible contact pad. The profiler assembly can have only one pneumatic cylinder, the pneumatic cylinder being mounted between one of the Y-shaped hubs and the lower surface of a respective flexible contact pad. In the case where the profiler assembly comprises three flexible contact pads, the pneumatic cylinder can be mounted between the Y-shaped hub and the lower surface of only the middle one of the flexible contact pads. The control device can be configured to cause the pneumatic cylinder to move the lever arm away from the centre of the lower surface of flexible contact pad to move the flexible contact pad from the first configuration to the second configuration and vice versa. The common shaft, lever arms, Y-shaped hubs, pairs of arms, flexible contact pads and pneumatic cylinder can be arranged such that the movement of one of the flexible contact pads between its first and second configuration caused by the pneumatic cylinder is transferred to the other flexible contact pads via the common shaft. The common shaft can be mounted on one side of a cradle, the opposite side of the cradle for being slidably mounted to a rail. The cradle can support the centre of the lower surface of each flexible contact pad. The profiler assembly can further comprise a rail on which the cradle is slidably mounted. The control device can be further configured to cause movement of the cradle along the rail.

In accordance with a fourth aspect of the present invention, there is provided a rotary carriage for use in the bag placing apparatus according to the first aspect, the rotary carnage comprising a pair of elongate hubs, each hub being rotationally mounted on a respective shaft via a respective sun gear such that the hubs are substantially parallel to, and spaced apart from, each other, a first open-topped crate pivotally mounted between the hubs at one end and a second open-topped crate pivotally mounted between the hubs at its other end, the first open-topped crate being coupled to each hub via a respective first gear wheel and the second open-topped crate being coupled to each hub via a respective second gear wheel, each hub carrying a first link arm and a first gear wheel arrangement mechanically coupled between the respective sun gear and first gear wheel and a second link arm and a second gear arrangement mechanically coupled between the respective sun gear and the respective second gear wheel, the first and second link arm and gear wheel arrangements being arranged and configured such that the rotary path of the hubs, at their ends, is substantially rectangular and the first and second open-topped crates remain substantially upright throughout a full rotation of the hubs.

Each hub can further comprise a central link arm extending across each hub such that the centre of each central link arm corresponds to the centre of each hub. The central link arm on each hub can be coupled to the first and second link arms on each hub. Each hub can further comprise a first longitudinal slot adjacent one end of the hub and a second longitudinal slot adjacent the other end of the hub. One end of the first link arm can be coupled to the central link arm and the other end of the first link arm can be slidably coupled within the first longitudinal slot. One end of the second link arm can be coupled to the central link arm and the other end of the second link arm can be slidably coupled within the second longitudinal slot. Rotation of each hub can cause said other ends of the first and second link arms to slide along their respective longitudinal slots such that the rotary path of said other ends of the first and second link arms is substantially rectangular. The first gear wheel can be mounted on the end of the first link arm that is slidably coupled within the first longitudinal slot, and the second gear wheel can be mounted on the end of the second link arm that is slidably coupled within the second longitudinal slot, such that the rotary path of the first and second open-topped crates is substantially rectangular. The centre of each sun gear can be fixed relative to each hub. The gear ratio between the sun gear and the first gear wheel can be 1:1, and the gear ratio between the sun gear and the second gear wheel can be 1:1. The first and second gear wheel arrangement can each comprise a plurality of gear wheels. The first link arm can be curved, and the first gear wheel and the first gear wheel arrangement can be arranged in a curved line along the length of the first link arm. The second link arm can be curved, and the second gear wheel and the second gear wheel arrangement can be arranged in a curved line along the length of the second link arm.

When the rotary carriage is orientated for use, and the elongate hubs are orientated vertically, the first and second open-topped crates can be substantially vertically aligned (one above the other). The first and second open-topped crates can follow the same rectangular rotary path as the ends of the hubs. The first and second open-topped crates can be 180° out of phase with each other.

The rotary carriage can further comprise a rotary drive means coupled to the centre of each hub.

These and other aspects of the present invention will be apparent from the following detailed description.

Brief Description of the Drawings

Embodiments of the present invention will now be described, by way of examples only, and with reference to the accompanying drawings, in which:

Figure 1 is a skeleton perspective view of a bag placing apparatus according to an exemplary embodiment of the present invention;

Figure 2 is a perspective view of the receiving surface of the apparatus of Figure 1;

Figures 3A, 3B and 3C are schematic plan views of the apparatus of Figure 1, illustrating three respective stages of a bag guidance process using the apparatus of Figure 1;

Figure 4 is a plan view illustrating the receiving surface of the apparatus of Figure 1;

Figure 4A is a schematic perspective view of a bar and paddle assembly for use in the apparatus of Figure 1;

Figure 5 is a skeleton perspective view of a bag placing apparatus according to an exemplary embodiment of the present invention;

Figure 6 is a schematic side perspective view of a rotary carriage for use in a bag placing apparatus according to an exemplary embodiment of the present invention;

Figure 6A is a schematic perspective view of a rotary hub of the rotary carriage of

Figure 6;

Figure 7 is a schematic perspective view of the rotary carriage of Figure 6, illustrating its rotational path, in use;

Figure 8 is a schematic perspective view of the rotary carriage of Figure 6, in situ, and illustrating a profiler assembly for use in a bag placing apparatus according to an exemplary embodiment of the present invention;

Figure 9 is a schematic side view of the rotary carriage and profiler assembly of Figure 8;

Figure 10 is a schematic side view of a profiler assembly for use in a bag placing apparatus according to an exemplary embodiment of the present invention;

Figure 11 is a schematic perspective view of the profiler assembly of Figure 10;

Figure 12A is an alternative schematic perspective view of the profiler assembly of Figure 10, showing the configuration of the flexible contact pads, in use, when a crate of the rotary carriage is full; and

Figure 12B is a schematic perspective view of the profiler assembly of Figure 12A, in use, when a crate of the rotary carriage is empty or nearly empty.

Detailed Description

Referring to Figures 1 to 4 of the drawings, there is illustrated, in accordance with a first aspect of the invention, a conveyor apparatus according to an exemplary embodiment of the present invention for an automated bagging machine. The apparatus comprises a stripper conveyor comprising a pair of chain belts 10 mounted around respective sets of rollers 12. In this exemplary embodiment, each set of rollers comprises four roller members arranged in a generally rectangular formation, with a continuous, closed-loop chain belt 10 looped around the four roller members such that the chain belt loop is in a generally rectangular formation, with each roller member located at a respective inner ‘corner’ of the loop. The conveyor comprises drive means (not shown) to drive the chain belts 10 around the rollers 12.

Each chain belt 10 comprises a plurality of link members 14, the link members 14 being articulated to form the above-mentioned loop. Each link member 14 comprises a main body having a pair of apertures 16 being substantially perpendicular to the direction of travel of the chain belt 10, when in use. A set of bars or rails 18 is mounted between the chain belts 10 in sets of two, each pair of bars 18 extending between two pairs of aligned apertures 16 in the chain belts 10, each end of a bar 18 extending through a respective aperture 16 to secure it transversely between the chain belts 10. A washer formed of a rubber block compound material is utilized between the link member 14 and the bars 18 (at the respective apertures 16) in order to minimise noise.

Collectively, a set of bars 18 form a receiving ‘surface’ for receiving a pre-made bag having an open end (for receiving a defined quantity of free flowing material into the bag at the filling station, which will not be described in detail herein). In fact, at least two receiving surfaces are mounted between the chain belts 10, although only one is shown in Figures 1 to 4. The receiving surfaces are substantially equally spaced apart. The above-mentioned drive means is used to drive the chain belts around the rollers in a single direction of travel, thus alternately bringing each receiving surface to the ‘upper’ end of the conveyor (when oriented for use). A single receiving surface is illustrated in Figures 1 to 4 located at the above-mentioned ‘upper’ surface of the conveyor.

In respect of each said receiving surface, a plurality of paddles 20 is slidably mounted on intermittent pairs of bars 18. Each receiving surface comprises at least 34 bars, and five pairs of paddles, each pair of paddles 20 being mounted on two adjacent bars and separated from the next pair of paddles by four bars, but the present invention is not necessarily intended to be limited in this regard.

Each pair of paddles 20 is mounted such that one of the paddles of a pair is nearer one of the chain belts 10 and the other paddle of the pair is nearer the other chain belts such that a ‘bag transporting path’ is defined on the receiving surface between respective pairs of paddles.

Referring additionally to figure 4A of the drawings, each paddle 20 comprises a body of a generally L-shaped cross-section, having a first plate-like portion 20a defining a pair of adjacent channels 22 therethrough, and a second plate-like portion 20b that is substantially perpendicular to the first plate-line portion 20a, such that the first platelike portion lies substantially parallel to the receiving surface formed by a set of bars or rails 18 and the second plate-like portion 20b, which is nearest the abovementioned ‘bag transporting path’ is perpendicular thereto and oriented such that the principal plane thereof is orthogonal to the plane defined by the receiving surface. The principal planes of the second portions 20b of each pair of paddles 20 are substantially parallel to, and facing, each other.

As stated above, each paddle 20 is mounted at an end of a pair of adjacent bars or rails 18 forming the receiving surface. Each of the pair of bars 18 extends through an aligned respective pair of channels 22 in the paddle 20 (through the first portion 20a and extending perpendicularly relative to the direction of travel of the conveyor when in use) such that each paddle is slidably mounted at a respective end of a pair of adjacent bars 18. Each paddle 20 additionally comprises an elongate pin 24, that extends orthogonally and generally centrally from the ‘bottom’ of the first plate-like portion 20a.

Referring back to Figures 1 to 4 of the drawings, the conveyor apparatus further comprises a pair of static proof guide rails 26 which effectively define the abovementioned ‘bag transporting path’. Each receiving surface, when positioned at the ‘upper’ end of the conveyor, has a first end 28a, nearest the bag separating apparatus (to be described hereinafter) and a second end 28b, nearest the filling station (not shown or described herein), the direction of travel of the chain belt conveyor being the direction defined from the first end 28a to the second end 28b. Each guide rail 26 is mounted at a respective side edge of the conveyor (substantially parallel to the chain belt at the upper end of the conveyor) extends from a location adjacent the first end 28a of the receiving surface (when it is located at the upper end of the conveyor) to a location adjacent the second end 28b. Each guide rail 26 comprises two integral sections, namely a first section 26a which extends from a location adjacent the first end 28a of the receiving surface (when it is located at the ‘upper’ end of the conveyor) and near a respective chain belt 10, and tapers inwardly (away from its respective chain belt 10) to an intermediate point 26c. The second section 26b of each guide rail 26 extends from a respective intermediate point 26c and runs substantially parallel to the direction of travel of the conveyor to a location adjacent the second end 28b of the receiving surface Thus, the first sections 26a of the guide rails 26 taper ‘inwardly’ toward each other, to their respective intermediate points 26c, which are transversely spaced apart from each other, and the second sections 26b extend substantially parallel to (and transversely spaced apart from) each other. Together, the pair of guide rails 26, and the receiving surface between them (when it is located at the upper end of the conveyor), define the path along which a bag will travel from the bag separating apparatus to the filling station. The paddles 20 are slidably mounted on respective pairs of bars or rails 18 such that their respective pins 24 engage with the adjacent guide rails 26, and can slide along the guide rails 26 as the conveyor moves. A wear strip (not shown) of, for example, polyethylene is provided along the pin engaging surface of the guide rails 26 to reduce friction and wear.

In use, as the conveyor moves the bag receiving surface formed by a set of rails 18 along its ‘upper’ end, the paddles 20 move along the guide rails 26 (via their respective guide-engaging pins 24) toward the centre of the receiving surface (i.e. along the tapered sections 26a of the guide rails 26 to the straight sections 26b) which, in use, acts to centre and correctly align a bag travelling on the receiving surface from a location between the tapered sections 26a of the guide rails to a location between the straight sections 26b thereof. Even if the bag is misaligned when it comes from the bag separating apparatus and is deposited on the receiving surface between the tapered sections 26a of the guide rails 26, it will be centralized and aligned by the paddles 20 by the time it reaches the filling station at the end of the straight sections 26b of the guide rails 26.

Referring specifically to Figure 3 of the drawings, at Figure 3A, a misaligned bag 30, deposited by the bag separating apparatus (not shown) can be seen between the paddles 20 just as it reaches the space defined between the intermediate points 26c of the guide rails 26 (i.e. just before it reaches the space between the straight (second) sections 26b of the guide rails 26). As the conveyor continues to move the bag toward the filling station (not shown), the paddles 20 at the intermediate points 26c of the guide rails 26 act to straighten and align the bag 30 such that, as it enters the space between the second sections 26b of the guide rails 26, it is correctly aligned (see Figure 3B). the bag 30 is then retained in this aligned configuration as it continues to move, and until it is presented to the filling station (see Figure 3C). At this point, the bag is removed from the rails 18 by a lifting component of the filling station (not shown) and the conveyor moves the set of rails 18 forming the receiving surface down and away from the ‘upper’ surface, and brings the second receiving surface up (on the other side) toward the upper surface, ready to receive another bag.

Thus, the space between the pairs of paddles 20 and guide rails 26 is wider at the ‘back’ (nearest the bag separating apparatus) than at the ‘front’ (nearest the filling station), so it does not matter if the bag is misaligned when it is presented from the bag separating apparatus: the paddles move in toward the centre as the conveyor moves, acting to centralize and align the bag. Thus, this aspect of the present invention provides guaranteed location/alignment of each bag. This is achieved with a required travel path of the bag (between the stripping apparatus and a datum at which an arm will pick up the bag and present it to the filling spout of a filling station) which is less than that of the prior art. This, in turn, has the effect of reducing the overall footprint of the bagging machine and also reducing the cycle time for transporting each bag from the stack to the datum for onward transport to the filling station. Furthermore, because the paddles 20 are mounted on the bars or rails 18 via the channels 22 (i.e. the paddles 20 are ‘wrapped around’ the rails 18), a bag cannot be caught or trapped under them, thereby further decreasing the likelihood of a malfunction.

Thus, and to summarise, the first aspect of the invention relates to a conveyor apparatus that centralises, squares and transports individual pre-made bags to a datum to allow arms to receive each bag before presenting it to a filling spout in an automated machine for packaging materials such as granular, aggregate and powders, in pre-made plastic (e.g. polypropylene), hessian or paper bags. In prior art systems, the operator places a (relatively small) stack of bags into the machine, a stripping conveyor removes a single bag from the pile by use of vacuum suckers and, once the bag is above a stripping conveyor, the suckers let go of the bag allowing it to travel on top of the stripping conveyor’s rails to a datum (where it is collected for presentation to a filling spout). Due to the limp nature of individual premade bags, guides which sit slightly above the stripping conveyor rails are used to align and centralise the bags over a long distance. As the thickness of a single bag is typically less than 1mm, there is a tendency (in prior art arrangements) for the bags to go under the guides and, therefore, not reach the datum in the correct position which may cause the presentation arms to the filling station to miss the bag. This aspect of the invention, as described by way of example above, circumvents the risk of bag misalignment and also reduces the required travel path of the bag in order to achieve this, thus reducing the overall footprint of the machine relative to prior art arrangements. Furthermore, the cycle time for transporting individual bags is reduced (because the travel path is reduced) and the reliability of positioning the bag for the next process is increased, without requiring operator intervention. This is achieved, in accordance with this aspect of the invention, by the use of sliding paddles on the stripping conveyor’s rails which move inward whilst a bag is in transit. Pairs of paddles move inward in tandem (relative to the bag), squaring and pushing a bag on the rails into the centre. The paddles themselves surround the rails, thus preventing a bag from going underneath the guiding system. The guide rail is underslung beneath the stripping conveyor’s rails, which allows the sliding paddles to move in and ensures that they position the bag correctly.

In the prior art, there are currently two principal methods of loading bags into openmouthed bagging machines:

1. To reduce manual loading frequency, a large volume of bags are placed into a fully guided crate, however, due to the natural lie of the bags, the sides and back become higher than the centre of the bags due to the depth of the accumulated bags. This causes problems where suckers taking the top bag can fail to grip it (because they are presented with a concave top surface). This great depth of bags also reduces the cycle time of the machine as the crate empties because the suckers must travel further into the crate as the stack is depleted. Changing between two crates requires either a large horizontal rotation or a scuttle system where the crates are loaded individually from either side of the machine.

2. Small packs of bags approximately 100mm high are loaded onto a conveyor (in alternative embodiments of the prior art) and moved into the machine under the stripping conveyor by means of a belt. Because the stack height is relatively small, the profile of the top bag does not alter greatly, and the shorter travel distance of the suckers has little effect on the speed of the machine. However, the use of a belt drive results in a loss of the guidance and datum provided by the crate, as well as requiring a large amount of room to hold the same volume.

The second and third aspects of the present invention seek to address at least some of these problems. Referring now to Figures 5 to 12B of the drawings, there is illustrated, in accordance with second and third aspects of the invention, a bag storage and transport apparatus according to an exemplary embodiment of the present invention for an automated bagging machine.

The apparatus comprises a rotary carriage 100 formed of two open-ended crates 102 mounted at respective opposing ends of a pair of rotary units 104. Referring specifically to Figures 6, 6A and 7 of the drawings, each rotary unit 104 comprises an elongate hub 106 being of generally rectangular configuration and having first and second longitudinally spaced apart ends. The elongate hub 106 is coupled, at its centre, to a rotary drive means (not shown). The hub 106 comprises an elongate central link arm 108, mounted between respective ends of a pair of distal link arms 110. The other end of each distal link arm 110 is slidably coupled within a longitudinal slot 112 adjacent a respective end of the hub 106. The central link arm 108 extends across the rectangular hub 106 (from one side to the other) such that its centre corresponds with a central location at which the rotary drive means is coupled. The centre of the central link arm 108 is coupled to the rotary drive means at that central location. The central link arm 108 is coupled to each said distal link arm 110 with a first respective gear wheel 113 therebetween. The first gear wheel 113 on each distal link arm 110 is mechanically coupled to a second gear wheel 114 mounted adjacent thereto on the distal link arm 110. The second gear wheel 114 on each distal link arm 110 is mechanically coupled to a third gearwheel 116 mounted adjacent thereto on the distal link arm 110. Finally, the third gear wheel 116 on each distal link arm 110 is mechanically coupled to a fourth gear wheel 118 mounted on the distal link arm 110 at the end at which it is slidably coupled within the slot 112 at a respective end of the hub 106. The four gear wheels 113, 114, 116, 118 on each distal link arm 110 are arranged in a slightly curved line along the length of the distal link arm 110, the distal link arms 110 being similarly profiled.

The second and third gear wheels 114, 116 on each distal link arm 110 are of substantially the same size, the first gear wheel 113 is slightly larger than the second and third gear wheels 114, 116, and the fourth gear wheel 118 is larger again. A fifth gear wheel (or ‘sun gear’) 120 is mounted over the centre of the hub 106 and fixed. The sun gear 120, which is substantially the same size as the fourth gear wheels 118, is mechanically coupled between the two first gear wheels 113. The resultant gear ratio is 1:1.

When the rotary drive means is operable, it acts to rotate the central link arm 108 (at its centre). This causes the hub 106 to rotate, but also causes operation of the gear arrangement (comprising the two sets of first to fourth gear wheels 113, 114, 116, 118), which causes the end of each distal link arm 110 to slide along its respective longitudinal slot 112 at the end of the hub 106. The resultant rotary path 122 is substantially rectangular (see particularly Figure 7 of the drawings).

The rotary carriage 100 is, as stated above, comprised of a pair of open-topped crates 102 mounted between a pair of opposing, spaced-apart, parallel rotary units 104 of the type described above. Each crate 102 is mounted between corresponding ends of the pair of rotary units 104. When the rotary units are oriented vertically (relative to when the apparatus is oriented for use), the crates 102 are substantially aligned, one above the other. As the rotary units follow the defined ‘rectangular’ path 122, the crates 102 follow the same path, remaining substantially hohzontal/uphght (i.e. with their open ends facing upward) throughout the rotary cycle, and effectively 180° out of phase with each other.

Referring to Figures 5, 8 and 9 of the drawings, the rotary carriage 100 is mounted within the stripping conveyor defined by the pair of chain belts 10. The centre of each hub 106 is located between the chain belts 10 and below the bag receiving surface region, such that the axis of rotation of the rotary carriage is substantially parallel to the direction of travel of the stripping conveyor. The arrangement is dimensioned such that, in use, and at any one time, one of the crates 102 travels substantially vertically upward at the side of the conveyor, from a lowest position (or ‘corner’ of the rectangular rotary path 122) to an upper position (at a top ‘corner’ of the rectangular rotary path) in which the top of the crate 102 is closer to (but still below) the bag receiving surface region. Upon further rotation, it travels horizontally, beneath the bag receiving region, to the opposite “corner” of the rectangular rotary cycle, vertically downward to the lower “corner” of the rectangular rotary cycle, and, finally, horizontally, out from under the bag receiving region, to the opposite “comer” of the rectangular rotary cycle, before the cycle starts again. The other crate 102 follows the same path, but 180° out of phase.

It will be recalled, from the foregoing description, that the stripping conveyor comprises a pair of sets of adjacent rails 18, each set defining a bag receiving surface when it is presented at the ‘upper’ end of the conveyor, and each set of rails being separated by a space along the continuous chain belt conveyor.

The rotary carriage 100 is mounted off-centre within the stripping conveyor defined by the chain belts 10, in the sense that each crate 102, when it is located below the bag receiving region of the conveyor, is located nearer the first end 28a than the second end 28b, i.e. closer to the ‘wide’ end of the guide rails 26 than the narrower end. The bag stripping cycle comprises the use of a vacuum sucker to lift a topmost bag in a stack of bags in a crate 102 and place it at the ‘wide’ end of a bag receiving surface formed by a set of rails 18, to be centralized, aligned and then presented to a filling station. The ‘current’ stack of bags is located in the crate 102 located at the ‘upper corner’ of the rectangular rotary path 122 and directly below the bag receiving region of the conveyor. From here, and with the chain belt conveyor operating continuously, there will, alternately, be a set of rails 18 and a gap directly above the stack of bags. The cycle is synchronised such that, when there is a gap, a vacuum sucker picks up the topmost bag from the stack in the crate below, and when the set of rails 18 moves in below it, it deposits the bag at the ‘wide’ end so that it is centralized and aligned as the set of rails 18 travels onward on the conveyor. Then, the bag is taken at the end of the bag receiving region, to be presented to the filling station. In the meantime, another gap appears over the stack of bags and the cycle begins again; thus providing a continuous cycle and optimising machine cycle times.

The rotary carriage 100 remains stationary whilst a stack of bags is being unloaded. Distance measuring sensors (not shown) detect the bag stack height in the crate and, once a crate 102 is empty, the rotary carriage is caused to rotate until the next (full) crate 102 is presented adjacent the upper end of the conveyor, and the unloading process begins again. Whilst one crate 102 is in the unloading position, adjacent the upper end of the conveyor, the other crate is at a location diagonally opposite (relative to the rectangular rotary path 122), i.e. at a low level, underneath the bag receiving surface region, where it can be conveniently re-loaded with a new stack of bags. Thus, the machine can always be re-loaded at the same location and at the same side of the machine.

Referring to Figures 1, and 8 to 12B, yet another feature of this exemplary embodiment of the present invention is a profiler assembly 200. The profiler assembly 200 is mounted, for vertical movement (relative to the apparatus when oriented for use), on a set of vertical rails 202 located at one side of the conveyor defined by the chain belts 10.

Referring specifically to Figures 10 to 13 of the drawings, the profiler assembly 200 comprises a set of three profiler members 204 arranged in side-by-side, spaced apart relation.

Each profiler member 203 comprises an elongate, generally rectangular flexible contact pad 204 mounted on a pair of thin arms 206. Each arm 206 is pivotally mounted, at a first end, to the lower surface of the contact pad 204 (relative to the profiler assembly 200, when it is oriented for use). The pivotal coupling 205a between each arm 206 and the flexible contact pad 204 is at a different location along the length of the flexible contact pad 204, the pivotal couplings 205a being longitudinally aligned and substantially equally spaced from the centre of the flexible contact pad 204. The opposite, second ends of the arms 206 are pivotally coupled at respective ends of a generally Y shaped hub 208. The arms 206 are angled toward each other (from the first end to the second end). As can be seen in Figure 11 of the drawings, a pneumatic cylinder 210 is mounted between the Y-shaped hub 208 and the ‘lower’ surface of the flexible contact pad 204 of just the middle one of the three profiler members 203.

A lever arm 212 is coupled at one end (the ‘distal’ end) to each Y shaped hub 208, each lever arm 212 being substantially parallel to the longitudinal axis of the respective flexible contact pad 204, such that the assembly 200 effectively comprises three such lever arms 212 arranged in parallel, transversely aligned and spaced apart relation. The opposing ends of the lever arms 212 are rotationally coupled to a common shaft 214 that extends orthogonally to the longitudinal axis of the lever arms 212 and flexible contact pads 204. The common shaft 214 is mounted on one side of a cradle 216, the opposite side of the cradle 216 being slidably mounted to the above-mentioned vertical rails 202.

As can be seen in Figure 8, for example, the profiler assembly 200 is located below a crate 102 when it is located beneath the receiving surface of the bag placing apparatus, such that the flexible contact pads 204 of the profiler members 203 extend through respective slots or gaps in the base of the crates 102. When the ‘current’ crate102 (i.e. the crate 102 from which bags are currently being separated and placed on the receiving surface as described above) is full of bags, the ‘sagging’ described above is at a maximum, and the resultant concave profile of the upper surface of the stack of bags is at its most pronounced. Accordingly, the concave profile of the lower surface of the stack is also at its most pronounced. To counteract this, the flexible contact pad 204 of the profiler assembly 200, which bear upwardly on the lower surface of the stack, has a convex profile, as shown in Figures 11 and 12A, for example. The convex profile of the flexible contact pads 204 bearing upwardly on the convex profile of the lower surface of the stack of bags has the effect of pushing the central region of the bags upward, and flattening out the upper surface of the stack, thus ensuring that the vacuum sucker action is reliably and consistently effective.

As the stack of bags is depleted during the bag placing operation, and the ‘sagging’ becomes less pronounced, the cradle 216 rises up the rails 202 and the pneumatic cylinder 210 causes the central lever arm to be moved downwardly, pulling the flexible contact pad 204, thus causing the arms 206 to pivot, within their limits, at their first ends (away from each other) and gradually flattening out the flexible contact pad 204 to match the gradual flattening of the central profile of the bags in the crate 102. The movement of the arms 206 of the central profiler member 202 is transferred to the other two profiler members 203 via the common shaft 214. . The above-mentioned distance measuring sensors (not shown) detect the bag height in the crate and signals therefrom control the operation of the profiler assembly 200. Once the crate is virtually empty, and the remaining bags present a substantially flat upper surface, the flexible contact pads 204 are completely flat, as shown in Figure 12B.

Once the crate 102 is completely empty, the rotary carriage operates to bring the next full crate to the operational position, beneath the receiving surface, and the profiler assembly 200 returns to the start position, with the flexible contact pads 204 having the most curved profile, as illustrated schematically in Figure 12A, and the bag placing process starts again with the new crate (full of bags).

Thus, to overcome the issues outlined above in relation to the prior art, the abovedescribed exemplary embodiment incorporating the second and third aspects of the present invention provides an ‘up and over’ rotary system that allows each crate to pass over the top of the other (under the stripping conveyor), thereby requiring a minimal footprint, whilst enabling the operator to load from a single side of the machine. Furthermore, a profiler is used to lift the bags upwards toward the open top of the crate, as the stack is depleted ensuring that the top of the stack remains a constant distance from the stripping conveyor. Distance measuring sensors detect the bag stack height in the crate as well as the deformation caused by the thicker bag edges. The profiler has flexible contact pads which are linked to a pneumatic cylinder. When a difference between the edges and the centre of the pack is detected, the cylinder alters the shape of the profiler, thus ensuring that the top bag is always flat.

It will be apparent to a person skilled in the art, from the foregoing description, that modifications and variations can be made to the described embodiments without departing from the scope of the invention as defined by the appended claims.

Claims

1. A bag placing apparatus for a packing machine for packaging free-flowing material in pre-made bags, the bag placing apparatus comprising:

a conveyer comprising:

a pair of laterally spaced apart guide rails located along an edge of said rectangular rotary path and extending in the direction of travel of said rotating platform, each guide rail having at least an first profile and a second profile along its length, and wherein the lateral space between the guide rails at said first profile is greater than that at said second profile; and a plurality of paddle members mounted at longitudinally spaced apart locations on said receiving surface, each paddle member having a body portion and a guide engaging member and being slidably mounted on a respective bar via an aperture in said body portion thereof, said guide engaging member being coupled at a first end to said body portion and configured to engage a respective guide rail, in use, for movement therealong;

a rotary carriage mounted within the conveyor, the rotary carriage comprising: a pair of elongate hubs, each hub being rotationally mounted on a respective shaft via a respective sun gear such that the hubs are substantially parallel to, and spaced apart from, each other;

at least one profiler member comprising a flexible contact member having an outward, operational surface and being mounted on a support assembly, the support assembly being configured, in use, to exert a force on the flexible contact pad so as to urge said operational surface of said flexible contact pad against the bottom of a pile of pre-made bags contained within the first or second open-topped crate at a operation position during a bag placing operation, the flexible contact pad being gradually movable from a first configuration, in which the flexible contact pad presents a convex operational surface, and a second configuration in which said operational surface is substantially flat, the profiler assembly further comprising a control device configured, in use, to cause movement of said flexible contact pad from said first configuration to said second configuration as said pile of bags is depleted during said bag placing process.

2. A bag placing apparatus according to claim 1, wherein the axis of rotation of the rotary carriage is substantially orthogonal to the first axis of the conveyor.

3. A bag placing apparatus according to claim 1 or claim 2, wherein the conveyor further comprises a pair of chain belts that define the generally rectangular rotary path of the rotating platform, wherein the set of parallel bars is mounted between the pair of chain belts.

4. A bag placing apparatus according to claim 3, wherein the rotary carriage is mounted within the conveyer defined by the pair of chain belts.

5. A bag placing apparatus according to claim 4, wherein the centre of each hub is located between the pair of chain belts.

6. A bag placing apparatus according to any one of the preceding claims, wherein the first and second open-topped crates are arranged such that they follow the same substantially rectangular rotary path as the ends of the hubs and are 180° out of phase with each other.

7. A bag placing apparatus according to any one of the preceding claims, wherein the conveyor and the rotary carriage are dimensioned and arranged such that such that when the bag placing apparatus is orientated for use, the upper edge of the rotary path of the first and second open-topped crates passes horizontally beneath the upper edge of the rectangular rotary path of the rotating platform

8. A bag placing apparatus according to any one of the preceding claims, wherein the conveyor and the rotary carriage are dimensioned and arranged such that when the bag placing apparatus is orientated for use, the first and second open-topped crates are movable in turn to the operating position corresponding to a position directly below a bag receiving region of the conveyor, the bag receiving region corresponding to the upper edge of the rectangular rotary path of the rotating platform.

9. A bag placing apparatus according to claim 8, wherein when the first or second open-topped crate is at the operating position, it is located at an upper corner of its rotary path, and the other of the first and second open-topped crates is located at a lower corner of its rotary path, diagonally opposite the first or second open-topped crate at the operating position.

10. A bag placing apparatus according to any one of the preceding claims, wherein the profiler assembly is mounted for vertical movement relative to the bag placing apparatus when orientated for use.

11. A bag placing apparatus according to any one of the preceding claims, wherein each of the first and second open-topped crates comprises a base with a slot or gap for allowing the flexible contact pad of the profiler assembly to extend therethrough.

12. A bag placing apparatus according to claim 11, wherein the profiler assembly is positioned relative to the rotary carriage such that when one of the first and second open-topped crates is at the operating position, the profiler assembly is moveable to extend the flexible contact pad through the slot or gap in the base of said one of the first and second open-topped crates at the operating position.

13. A bag placing apparatus according to any one of the preceding claims, wherein the bag placing apparatus comprises a distance measuring sensor configured to detect the height of a stack of bags contained within the first or second open-topped crate when at the operating position.

14. A bag placing apparatus according to claim 13, wherein the control device of the profiler assembly is configured to control the vertical position of the flexible contact pad relative to the first or second open-topped crate when at the operating position based on a signal received from the distance measuring sensor.

15. A bag placing apparatus according any one of the preceding claims, wherein the distance measuring sensor is configured to detect a difference in the height between the centre of a stack of bags and the edges of a stack of bags contained within the first or second open-topped crate when at the operating position.

16. A bag placing apparatus according to claim 15, wherein the control device of the profiler assembly is configured to move the flexible contact pad between its first configuration and its second configuration based on a signal received from the distance measuring sensor.

17. A bag placing apparatus according to any one of the preceding claims, wherein the rotary carriage is configured to move the first or second opentopped crate to the operating position when the distance measuring sensor detects that the first or second open-topped crate currently at the operating 5 position is empty; and the rotary carriage is configured to remain stationary when the distance measuring sensor detects that the first or second opentopped crate at the operating position is not empty.

18. A bag placing apparatus according to any one of the preceding claims, wherein the conveyor comprises a plurality of sets of parallel bars to form a io plurality of generally planar receiving surfaces, each set of parallel bars being separated by a space.

19. A bag placing apparatus according to any one of the preceding claims, further comprising a vacuum sucker configured to pick up the topmost bag from a stack of bags contained in the first or second open-topped crate at the

15 operating position and place the topmost bag on to the, or one of the, generally planar receiving surfaces of the conveyor as it travels along its rotary path.