WO2000071418A2

WO2000071418A2 - Bag handling apparatus

Info

Publication number: WO2000071418A2
Application number: PCT/GB2000/001838
Authority: WO
Inventors: Michael Alan Marriott
Original assignee: Clyde Materials Handling Limited
Priority date: 1999-05-19
Filing date: 2000-05-19
Publication date: 2000-11-30
Also published as: GB9911589D0; WO2000071418A3; GB2356843A; AU4770600A; GB0101266D0

Abstract

The bag place apparatus comprises a bag magazine that raises a bag stack to compensate for reduction in height of a bag stack, a droop correction arrangement to prevent peripheral bag edge droop and a launch arrangement for launching a bag over side guides of a bag filling assembly. The bagplacer apparatus enables shortening of both (i) the distance from the bag stack to a pincer presentation position of a pick-up frame and (ii) the launch distance from pincer presentation /grip position to the bag holder of the filling apparatus.

Description

BAG HANDLING APPARATUS FIELD OF THE INVENTION

The present invention relates to bag placing and filling apparatuses for use in filling open mouth bags or sacks with, in particular, dry contents.

BACKGROUND OF THE INVENTION

Open mouth bags or sacks may be filled with particulate materials, for example animal feed, chemicals, fertiliser, food ingredients, sand or gravel, using automated apparatus in which a bag placer transfers an empty bag from a magazine to the spout of a bag filling device. The filling device fills a metered quantity of material into the bag, which is usually subjected to further automated operations, including closing (for example by sewing) and palletising.

BACKGROUND ART

Bag placers, therefore, provide automatic handling of open-mouthed bags (sometimes referred to as sacks, although the term "bag" will be used in this specification) by placing them on the bagholder of an associated weigher or filler. The bagplacer has a bag magazine for containing a stack of empty bags. An empty bag is lifted from the empty bag stack by means of vacuum-activated suction pads on an upper or pick-up frame, and is then partially opened by the combined action of the suction pads on the pick-up frame and suction pads on an underside frame. Such opening of the bag allows the insertion of a pincer assembly which opens out to firmly grip and open the bag. The pincer assembly is coupled to a launcher which moves the pincer assembly to position the gripped bag onto the bagholder of the bagfiller, where the bag is clamped into position around a spout prior to filling of the bag.

In commercially available bagplacers, positioning of the various mechanical parts of the machine is by means of pneumatic or hydraulic cylinders, and especially by means of pneumatic cylinders which are controlled by solenoid-operated air valves in response to signals from the programmable logic controller (P C) control system. The positions of the mechanical parts are detected by proximity sensors which indicate the current mechanical status of the machine to the PLC system. As an alternative to hydraulic or pneumatic cylinders, an electric motor may be used.

The above-described features of bagplacers are of course very familiar to those skilled in the art and can be found, for example, in the Richard Simon "Bagplacer Mark 3", made by Clyde Richard Simon Limited, of Basford, Nottingham NG6 ODT, United Kingdom.

It would be desirable to increase the speed of such bagplacing/filling apparatus (which is typically about 720 bags per hour). It would also be desirable to simplify the apparatus where possible, in order to reduce cost and increase reliability. The present inventors have appreciated that improvements in design capable of contributing to meeting these aims can be made by modifications to three features of a type of bagplacer now on the market, exemplified by the Richard Simon "Bagplacer Mark 3". These current arrangements will now be described in more detail:

The Magazine

A bag magazine comprises one or more compartments to contain stacks of bags lying on one of their side faces. In essence, a bag magazine comprises one or more platforms, the or each of which is for supporting a stack of bags. The bag pick-up frame descends to the top of the stack to pick up the topmost bag. In some machines there is a single compartment and in others a plurality of compartments so that one compartment can be filled while the bagplacer empties the other. For example, a typical machine has a wheel-mounted two compartment magazine, which is manually moved to change the compartment positioned for the lifting frame. Less frequently, automatic indexing magazines are used: these comprise a number of compartments (optionally on a conveyor assembly) and, as one stack of bags is exhausted, the magazine automatically indexes to the next full stack.

Droop Corrector

After the suction pads of the pick-up frame have gripped the top face of a bag, the frame lifts to expose the under face of the bag, which is then contacted by the suction pads of the underside frame, before the separation between the two frames is increased to cause the bag to open sufficiently for the pincers to enter it. The mouth of the bag can droop open (i.e. the under face of the bag can droop downwards) before the bag is contacted by the underside frame suction pads; in this case, instead of contacting the under face, the underside suction pads can enter the partially open bag mouth and contact the lower surface of the upper bag wall.

Such droop is corrected by means of arms which swing upwards when the bag has been lifted, to lift and close the bottom edge of the bag mouth.

Launcher Action

The function of the launcher is to position the bag on the bagfiller, after the bag has been gripped by the pincer assembly. The launcher moves the pincers appropriately to position the bag on the bagholder of the filler. The pincer assembly is mounted on the launcher, which is actuated to swing the pincer assembly through an arc, bringing the bag mouth from an approximately horizontal orientation to a more upright one, which is typically substantially vertical.

The bagfiller has a feed spout/bag holder assembly and, spaced below the assembly, upright side guides to position the body of the bag as it is filled and support it after release from the bagholder. In practice, the side guides comprise parallel plates positioned on either side of a conveyor belt which transports the filled bags from the bagfiller to, usually, automated downstream operations. In order to avoid the side guides obstructing movement of the pincers and/or the bag they are gripping, the side guides incorporate a gate which opens for the pincers to swing to the bagholder and close after the pincers have swung back.

SUMMARY OF THE INVENTION

Bag Magazine

According to a first aspect of the invention there is provided a bag placer apparatus having a bag magazine which is characterised in that, in use, a bag stack is raised to adjust for reduction in bag stack height.

Reference herein to bag is intended to include pillow and/or gusseted bags or sacks.

Preferably, the bag placer apparatus further includes a stack height sensing device for monitoring the height of a bag stack. The stack height sensing device is operatively linked to a control system for controlling the raising of the stack.

The apparatus does not necessarily raise the bag stack to compensate precisely or continuously for the reduction in stack size as each bag is removed. Rather, the stack may be raised in a way which approximately compensates for the reduction in stack size. Thus, the top of the bag stack may be raised discontinuously by incremental amounts of from about 10 to about 60 mm and more usually of from about 10 to about 40 mm (e.g. about 20 to about 40 mm). The apparatus may comprise a bag pick-up frame capable of accommodating larger variation in the height of the stack top from the ground, for example, it may accommodate a variation of from about 5 to about 80 mm (e.g. about 5 to about 60 mm and often of at least about 10 mm) and typically about 20 to about 40 mm, i.e. the apparatus has a bag pick-up zone having a range for example of from about 5 to about 80mm, within which the top of the stack is maintained. Preferably, the bag placer apparatus also comprises a magazine empty sensor which is operatively linked to the control system to cause a fresh bag stack to be presented for bag removal (ie to have its top positioned in the bag pick-up zone). The senor may be optionally linked to an audio and/or visual alarm so as to alert an operator that the bag stack needs replenishing or replacing.

Preferably, the bag magazine comprises a bottom support surface or platform which in use supports the bag stack and is upwardly and downwardly moveable by means of a pneumatic, hydraulic or electric drive means.

Preferred apparatuses comprise magazines having a plurality of compartments. Each compartment comprises a respective bottom support surface or platform which is capable of being upwardly and downwardly moved by drive means, for example a pneumatic or hydraulic arrangement or an electric drive. Suitably, the magazine comprises a framework with which the support surfaces are associated and the drive means comprises a lifting member for lifting a selected support surface, the framework and the lifting member being movable relative to each other, whereby the lifting member may be brought into lifting relationship with the selected support surface.

Preferably, the framework additionally comprises guide means for maintaining the stack in position, more preferably the guide means comprises a plurality of posts.

Preferably, the drive means comprises an air cylinder.

Preferably, the upward movement of the support surface towards a bag lifting frame is controlled by a hydraulic speed control check cylinder.

Thus it will be appreciated that, in use, the bag support surface preferably moves from a first resting position towards the bag pick-up frame, most preferably in a controlled and relatively slow manner, to a second presenting position. The bag pick- up frame then moves towards the top of the bag stack and grips the upper surface of the uppermost bag in the stack before moving the uppermost bag away from the stack. Once several bags have been removed sequentially from the top of the stack, optionally in excess of the tolerance of stack height, the stack height sensing device relays height information to a control. The control then activates the drive means to raise the support surface towards the bag lifting frame to compensate for the height of removed bags. In this way the movement of the support surface is incremental during operation.

Preferably, the support surface moves towards the bag lifting frame in stepwise manner.

As the stack diminishes over a run any magazine empty detector activates the control to energise the air cylinder or other drive means to rapidly return the support surface to its first position and to cause a second bag-stacked magazine to be positioned to take the place of the depleted stack. In this way a continuum of bags are fed towards the bag lifting frame.

It will be appreciated that in the prior art the bag magazine is static during bag pick- up and the bag pick-up frame travels to the top of the bag stack, so that over the course of operation the distance that the bag pick-up frame has to travel is increased. Thus, at the end of a run the time taken to collect and grip a bag is significantly greater than at the start of an operation. The bag magazine of the present invention is of significant advantage in reducing the time taken to present a bag to the bag pick-up frame whereby the number of bags filled per hour of running operation may be increased.

According to a second aspect of the invention there is provided a bag-placer apparatus comprising means for supporting a stack of empty bags and operatively associated therewith a means for collecting a bag from the top of the stack, wherein the bag support means is adapted to travel from a first position to a second position closer to the bag collecting means and thereafter to move further towards the bag collecting means.

Preferably, the device of the second aspect of the invention further includes any one or more of the features of the first aspect of the invention.

According to a third aspect of the invention there is provided a method of presenting a bag stack to a bag lifting frame using the bag magazine of the first or second aspects of the invention comprising: (i) placing a stack of empty bags on an upper surface of a bag magazine platform in a first position,

(ii) moving the bag magazine platform towards the bag pick-up frame so as to enable the bag pick-up frame to engage and remove the uppermost bag of the stack to a downstream operation, (iii) continuing the operation of the pick-up frame whilst raising the magazine platform level so as to approximately compensate for the decrease in stack height,

(iv) sensing the bag stack height has diminished to an approximately zero bag level,

(v) returning the magazine platform to a the first position, and (vi) either replacing the empty magazine with another stacked magazine or replenishing the magazine platform with a stack of empty bags.

Droop Corrector

The droop control feature provided by the invention resides in the use, to control mouth droop in a bagplacer, of pick-up frame suction means for gripping bag mouths close to (or at) their side margins.

According to a fourth aspect of the invention, therefore, there is provided a bagplacer apparatus having a bag pick-up frame provided with suction means characterised in that the suction means is capable in use, of gripping an empty bag at peripheral margins of its upper surface at its mouth such as to control drooping of the mouth. Preferably, the suction means is arranged for the gripped marginal areas of a pick-up bag to be raised relative to an intermediate area.

Preferably, the suction means comprises suction pads or suction nozzles. In commercial machines, the suction pads will be mounted resiliently, usually by spring loading.

Preferably, suction pads for gripping the marginal areas of a pick-up bag are raised relative to intermediate suction pads.

Preferably, suction pads for gripping the marginal areas of a pick-up bag depend a marginally shorter distance from a support frame than those suction pads positioned inwardly therefrom, more preferably still the difference in height between the outermost suction pads and their inwardly positioned neighbours is in the region of about 2 to about 12 mm (e.g. about 5 to about 10 mm) and ideally about 8 mm.

Preferably, the suction pads comprise a front set for gripping the bag at its mouth and a rear set for gripping at a position closer tothe closed bag end. Ideally the front set of suction pads comprise at least three pads and normally four pads or more and the rear set, when present, at least two.

Preferably, the sets of suction pads are arranged so as to be in substantially parallel with one another.

Preferably, the bagplacer apparatus further includes an under-frame which is provided with suction pads. Ideally, the under-frame suction pads comprises at least two and normally three pads or more. Preferably, suction pads depending from the support frame and under-frame suction pads are aligned, so that in use, they are positioned so as to be substantially directly above one another.

Preferably, suction pads positioned inwardly from the peripheral/outermost suction pads on the support frame are directly aligned with at least two under-frame pads.

It will be understood that in preferred embodiments the arrangement of suction pads comprises a set of suction pads on the support frame some of which have under- frame suction pad equivalents or opposites, whereas others do not and can be considered as free. A typical arrangement for example is illustrated in the accompanying Figure 6, wherein the arrangement runs from right to left in the following unit manner, (a unit comprising at least one suction pad): unit 1 = free upper peripheral pad ; unit 2 = upper inwardly positioned pad with lower set equivalent; unit 3 = free lower set pad; unit 4 = upper inwardly positioned pad with lower set equivalent; unit 5 = free upper peripheral pad.

In some bagplacers the units are evenly spaced apart but in others the spacing is irregular.

Preferably, in use the suction means (e.g. pads) of the upper (pick-up) frame are applied to the uppermost bag of the stack and a suction force applied. The gripped bag is then lifted by the pick-up frame before the suction means of the under-frame is applied to the bag and a suction force applied. The suction force applied in juxtaposition to the side margins of the bag (normally meaning that applied by the pads for gripping the marginal areas) is usually then stopped in order to facilitate opening of the bag mouth. Next, the upper and lower suction means (usually sets of suction pads) are separated so that the bag mouth opens. In preferred apparatus, therefore, the opening bag is gripped at one or more (e.g. two) intermediate points along its upper surface and at a plurality of, e.g. three points along its lower surface. The number of suction points on the upper and lower surface of an empty bag is not intended to limit the scope of the application but merely to exemplify how the apparatus of the invention can correct bag droop.

According to a fifth aspect of the invention there is provided a bagplacer apparatus having a bag pick-up frame provided with three or more suction means for generating suction points the suction points being arranged so that at least the two outer peripheral suction points are marginally raised relative to suction point(s) positioned inwardly therefrom, so that in use an empty bag is gripped at edges of a bag mouth upper surface so as to correct bag droop.

Preferably, the apparatus of the fifth aspect of the invention further includes any one or more of the features of the fourth aspect of the invention.

According to a sixth aspect of the invention there is provided a method of bag droop correction using a bag-placer apparatus and the suction means arrangement of the fourth or fifth aspect of the invention.

Launcher Action

The invention further provides a bagplacer apparatus having pincer arms capable of being launched i.e. pivoted upwardly over the side guides of a bagfiller assembly.

Preferably, the pincer arms are capable of being traversed from a bag-grip position to a launch position i.e a position from which they are pivoted upwardly this position being closer to the bagfiller assembly than is the bag-grip position, traverse drive means being provided to move the pincer arms between the bag-grip and launch positions. The traverse drive means typically comprises an electric drive or a hydraulic arrangement and more usually a pneumatic arrangement.

The pincer arms are preferably each pivo tally mounted about a pivot axis for pivoting of their free ends towards and away from each other. The pincer arms may be so mounted on a launch member, for example a transverse shaft, which is arranged for rotation with the pincer arms whereby rotation of the launch member causes launching or "de-launching" i.e. return of the pincer arms to a bag grip position. Thus, the launch member is normally arranged for rotation about an axis perpendicular to the pivot axis of each pincer arm. Drive means, which is usually an electric drive or a hydraulic or, preferably, pneumatic arrangement, is provided to cause the launch member to rotate.

The launch member is also arranged for longitudinal movement together with the pincer arms, whereby such longitudinal movement can affect traverse of the pincer arms from the bag-grip position to the launch position, or vice-versa. Typically, the launch member is rotationally connected to a traverse means which is mounted for linear movement. In commercial practice, the launch member may comprise a transverse rod or shaft and the traverse means a pair of arms (eg rods), each of which is coupled via a bearing to a respective end of the transverse rod. The arms are suitably mounted for linear movement through runner blocks.

The pincer arms are coupled to a traverse drive means, e.g. an electric, hydraulic or, preferably, pneumatic arrangement, to cause traversing of the pincer arms. Suitably, the drive means is connected to the pincer arms via the launch member and, usually, the traverse means.

In one embodiment of the invention the apparatus further includes a pair of gripper means pivotally mounted on the launch member. Each gripper means is positioned outwardly of a respective pincer arm, between the pincer arm and an end of the transverse launch frame shaft. Each of the gripper means comprises a gripper arm, one end of which is provided with a pair of opposed pivoted gripper fingers.

The gripper fingers are arranged so that in a closed position a gripping surface of a first finger abuts a corresponding gripping surface of a second finger. In this way, in use and in a closed position the fingers are capable of gripping a part of a bag therebetween. It will be appreciated that this embodiment is particularly well suited to retaining edges of a gusset bag, especially the region where the gusset is formed in the bag.

Preferably, the gripping surface of the fingers is resiliently deformable or padded. The gripping surface of the fingers is ideally constructed of a suitable material which will allow retention of the bag without causing damage to the bag material itself, thus the fingers could be constructed of plastics or the like.

Preferably, the gripper fingers are actuated by a double acting pneumatic cylinder ideally coupled directly to the gripper fingers.

Preferably, movement of the gripper fingers is controlled by a solenoid air valve or the like, the valve is adapted to receive signals from the bagplacer apparatus's central programmable logic controller, thus it is possible to control the opening and/or closing of the gripper fingers at desired time points.

Preferably, at an end opposite to the gripper fingers the gripper arm is coupled to a pivot block so that the gripper arm is capable of pivoting movement towards the pincer arm. The pivot block is coupled to a traverse drive means, e.g. an electric, hydraulic or, preferably, pneumatic arrangement, to cause traversing of the gripper arms. Suitably, the drive means is connected to the gripper arms via the launch member and, usually, the traverse means.

The gripper means may be fixedly mounted on the launch member or alternatively they may be detachably mounted on the launch member so that the apparatus can easily be adapted for use with either pillow bags or gusset bags.

In a yet further aspect of the invention there is provided a kit of parts which includes a launch member, pincer arms and/or gripper means. One class of bagplacers included in the invention comprises: a pincer assembly comprising a pair of pincer arms; a rotary launch member to which the pincer arms are pivotally coupled for pincer movement and for rotation therewith; a traverse means to which the launch member is rotationally coupled and which is arranged for linear movement with the launch member and the pincer arms from a first position to a second position; pincer drive means for causing pincer movement of the pincer arms; launch drive means for causing rotation of the launch member; and traverse drive means for causing linear movement of the pincer arms, the launch member and the traverse means.

Each drive means may independently comprise an electric, pneumatic or hydraulic arrangement, especially an air cylinder. Preferably, the drive means are all connected to a common pneumatic or hydraulic system.

The launch member optionally comprises a transverse shaft rotationally mounted to the traverse means. The traverse means may comprise a pair of elongate arms, each mounted to a respective end of the transverse shaft.

Other Features included in the Invention

The apparatus of the invention may include any one or more of the inventive magazine, droop correction and launch arrangements described above. In particular, the use in a bagplacer of a combination of a magazine of the invention and a launcher arrangement of the invention beneficially enables shortening of both (i) the distance from the bag stack to the pincer presentation position of the pick-up frame and (ii) the launch distance from pincer presentation/grip position to the bag holder of the filling apparatus. The invention includes a product produced using any of the apparatuses of the invention.

The invention includes a product produced using any of the methods of invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example only with reference to the following Figures wherein:

Figure 1 illustrates an end view of a bagplacer apparatus according to the present invention;

Figure 2 illustrates a plan view of bag magazine and associated framework;

Figure 3 illustrates a front view of Figure 2;

Figure 4 illustrates a side view of Figures2 and 3;

Figure 5 illustrates a side view of Figure 1 ;

Figure 6 illustrates a front view of a bag lifting frame according to the present invention;

Figure 7 illustrates a side view of a bag lifting frame and launch assembly in accordance with the present invention;

Figure 8 illustrates a detailed representation of the launch assembly of Figure 7;

Figure 9 illustrates a detailed view of Figure 6; Figure 10 illustrates a plan view of a launch assembly;

Figure 11 illustrates a detailed plan view of the pincer arms of Figure 9;

Figure 12 illustrates the complete cycle of events of the bagplacer apparatus;

Figure 13 illustrates an alternative embodiment of Figure 9 including gripper means;

Figure 14 illustrates the gripper means of Figure 13; and

Figure 15 illustrates a partial cycle of events of the bagplacer apparatus of Figure 13.

Figures 1 to 11 and Figures 13 and 15 incorporate certain illustrative dimensions (in mm) which serve to provide more information about the shown apparatus but are of course in no way limiting. Similarly, illustrative but not limiting timings are shown in Figures 12 and 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The Figures illustrated a bagplacer which incorporates the following inventive features

• a magazine which raises the bag stack to adjust for reduction in the stack size as bags are lifted • a pick-up frame having a suction arrangement which provides peripheral suction at the bag mouth to control droop

• pincer arms which can be launched over the side guards of a bag filler, usually but not necessarily by virtue of being traversed from a bag grip position to a launch position. The illustrated apparatus may be modified to contain any one or two of these features. It normally has an automated control system, for example a PLC control system, which need not be described further.

Figure 1 is an end view of a bagplacer 1 comprising a bag magazine 2, in this case a twin compartment magazine comprising a first bag compartment 3 and a second bag compartment 4. As can be seen more clearly with the aid of Figures 2 and 3, the magazine comprises a framework 5, suitably made of steel and especially of angle iron, to which are welded or otherwise secured guides 6a, 6b, 6c, 6d defining the first compartment 3 and guides 7a, 7b, 7c, 7d defining the second compartment 4. The framework 5 has attached to each of its opposed sides a respective outwardly-open channel 8a, 8b. The channel 8a receives wheels 9a, 9b of a magazine front support 10 and the channel 8b receives wheels 9c, 9d of a magazine rear support 11. The framework 5 and channels 8a, 8b and their associated parts therefore form a carriage movable to and from along the front 10 and rear 11 magazine supports. Normally, carriage drive means, for example hydraulic or, preferably, air cylinders 18a, 18b are provided to move the carriage.

Each of the first 3 and second 4 bag compartments is provided with a respective support surface or bottom plate 12a, 12b, suitably made of rigid plastics material. The bottom plates 12a, 12b, rest freely on the framework 5 and have defined therein slots to accommodate the uprights of the guides 6a-d, 7a-d. The framework 5 has defined therein a through hole 13a, 13b below a centre portion of each of the bottom plates or platforms 12a, 12b.

Turning now to Figure 4, there is located under the framework 5 a drive means comprising a lifting cylinder 14 and, usually, a speed control check cylinder 15. The lifting cylinder 14 is suitably an air cylinder and the check cylinder is suitably a hydraulic cylinder. The cylinders 14 and 15 are mounted in a cylinder frame 16 which is secured to the framework 5 and at their upper ends are secured to a lifting member comprising a magazine lift frame 17 located, when in the rest position shown in Figure 4, in the through hole 13a under the bottom plate 12b of the second compartment 4.

The lifting cylinder 14 may be actuated to raise and lower the magazine lift frame 17 and hence the bottom plate 12b resting on the lift frame 17. The speed control check cylinder 15 serves to control upward movement of the lifting frame 17.

The magazine is provided with a magazine low sensor 19 for sensing the height of a bag stack, and with a magazine empty sensor 20, which is shown to be mounted on the lift frame 17 and to be a photoelectric sensor to which any stacked bags are exposed through a spy hole 21a, 21b in each bottom plate 12a, 12b.

In use, a stack of open-mouthed bags is placed horizontally on a platform of the magazine, ie on a bottom plate 12a or 12b of the illustrated apparatus, and more usually on all the platforms of the magazine. The carriage comprising the bottom plates 12a, 12b is positioned so that a selected one of the bottom plates is located above the lifting member (lift frame 17) and that the bag stack on the selected bottom plate is located in a bag pick-up zone where it is positioned suitably for a pick-up frame to be described later to pick bags up from it. The selected bottom plate and with it the bag stack may however have to be lifted by the lift frame 17 before the top 22 of the stack is positioned in the bag pick-up zone.

Once the stack top 22 is positioned in the bag pick-up zone, bags are taken from the stack until the magazine low sensor 19 detects that there are no bags in alignment with it. The air lifting cylinder 14 is then actuated to raise the lift frame 17 and hence the bag stack until the magazine low sensor is again covered by bags, at which time the lifting ceases or a predetermined time period commences at the end of which the lifting ceases. The hydraulic speed check cylinder 15 serves to control the lifting speed of the stack and stop its upward motion when desired. Such incremental or stepwise raising of the bag stack is repeated while bags remain. As the last bag is removed from the magazine compartment, the magazine empty sensor 20 detects the absence of any bags and, via its connection with a control system, causes the pneumatic lifting cylinder 14 to lower the platform (selected bottom plate). The magazine empty sensor 20 may be connected to an audible or visible alarm to alert an operator that the emptied compartment needs replenishing.

When the bottom plate (12b in the drawings) reaches its down or rest position, it is normally detected by a platform down sensor (not shown). The carriage comprising the framework 5, channels 8a, 8b and bottom plates 12a, 12b is then moved along the front 10 and rear 11 magazine supports by the carriage drive means so that the other filled compartment becomes positioned over the lift frame 17. The depleted magazine compartment may then be filled.

It will be appreciated that the essential feature of the illustrated apparatus is that the bag stack is raised to adjust the height of the stack top for reduction in the stack size. The illustrated apparatus raises the bag stack in increments, and preferred apparatus has a magazine low sensor (also called a bag height sensor)linked to a control system which causes the stack to be raised when the stack top falls below a set height. Similarly, preferred apparatus has a magazine empty sensor to enable automatic lowering of a platform after depletion of its bag stack. Alternatively, the apparatus may have means, especially a sensor, connected to the control system to cause the platform to be lowered when the number of bags remaining in the stack is close to zero.

The magazine does not necessarily have a plurality of compartments; if it does, it is conveniently in the form of a transversely moveable carriage having a plurality of liftable platforms. The carriage may then be moved after emptying of one compartment (depletion of one stack) to locate a loaded platform over a transversely fixed lifting member, which in turn lifts the loaded platform to maintain its stack top in the bag pick up zone. Irrespective of the magazine type, the bag pick-up zone typically has a vertical range of between 20 and 60mm, e.g. 30 and 50mm, within which range the pick-up frame can pick up bags from the stack. Preferred multi- compartment apparatus has a platform down sensor to detect when a platform has been lowered to its down or rest position, upon which the control system causes the other or another platform, loaded with bags, to be positioned for lifting, e.g. by moving a carriage as described above.

Turning now to Figure 5, there is shown a pick-up or upper frame 23 provided with a plurality of vacuum-activated suction pads. In the illustrated apparatus there is a front row 24 and a rear row 25 of suction pads (also known as suction cups). As can be seen from Figure 6, at least the front row 24 comprises a pair of inner suction pads 26a, 26b and a pair of outer pads 27a, 27b. The suction pads are all shown to be resiliently mounted for up and down movement by means of spring loading.

The upper frame 23 is moved by drive means in a similar way to the upper frame of existing bagplacers, to pick-up bags from a bag stack and present them to pincers. Suitably the drive means comprises an electric motor or a hydraulic or especially pneumatic arrangement, shown to comprise a bag lift air cylinder 28 and two bag opening air cylinders 29a, 29b. The upper frame is provided with a vacuum on sensor which is a photosensor 30 (Fig 5) in the illustrated embodiment.

In use, the drive means lowers the upper frame 23 until the suction pads contact the bags, as detected by the vacuum on sensor. In the case of the illustrated apparatus, the two bag opening cylinders 29a, 29b initially lower the upper frame 23 together with the bag lift cylinder 28. After the bag opening cylinders 29a, 29b have reached the limit of their extent, the bag lift cylinder 28 continues to lower the upper frame 23 until the vacuum on sensor 30 detects the top 22 of the bag stack. Vacuum is then created in the upper frame suction pads of the front 24 and rear 25 rows. The upper surface of the bag mouth becomes attached to the upper frame front suction pads 26a-b, 27a-b. The upper frame drive means is then activated and, more specifically, the bag lift cylinder 28 is actuated, causing the upper frame 23 to rise and with it the bag 31 gripped by the suction pads.

Whereas existing bagplacers have a front suction pad row consisting of two or three suction pads spaced inwardly from the side margins of the bag, the upper frame 23 of the bagplacer of the invention has suction pads or suction nozzles 27a, 27b positioned to be adjacent to the edges of the bag 31, ie to grip the bag mouth at its side margins. This has the effect of removing the freedom of the bag mouth to droop by a significant amount.

Preferably, the outer suction pads 27a and 27b are located slightly upward of the inner pads 26a, 26b, in order further to help resist bag droop. For example, in the illustrated embodiment the outer suction pads 27a, 27b are up to 12mm higher than the inner suction pads 26a, 26b and preferably between 2 and 12mm higher. In the most preferred apparatus, the outer suction pads 27a, 27b are about 8mm higher than the inner pads 26a, 26b.

It will be appreciated, therefore, that the essential feature of the illustrated pick-up or upper frame 23 is that it is provided with suction pads located to grip the upper bag wall defining the bag mouth at its peripheral margins. Normally, there are in addition one or more suction pads positioned intermediate the peripheral suction pads and, most preferably, the intermediate suction pads are located slightly lower than the peripheral suction pads.

Typically, bagplacers are manufactured for bag filling and palletising lines for bags of predetermined size. In such cases, it will be known where the peripheral suction pads must be located in order to contact the margins of the bags. However, in some machines of the invention, the peripheral suction pads are adjustable, so that their position may be changed to match different sizes and types of bags, for example gusset bags. Looking now at Figures 6 and 7, the illustrated apparatus comprises an underframe 32 similar to known underframes and provided with a plurality of suction pads 33 a, 33b, 33c. The underframe 32 pivots from brackets 34a, 34b and is coupled to drive means, normally comprising an electric motor or a hydraulic and preferably pneumatic cylinder 35.

The bagplacer further comprises a pincer assembly, which can be understood most clearly from Figures 7, 8, 9, 10, 11, and 13. The pincer assembly comprises two pincer arms 36a, 36b having at their free ends pincers 37a, 37b which suitably have a rubber or soft plastics covering. The pincer arms 36a, 36b pivot around pincer arm bearing assemblies 38a, 38b for movement towards and away from each other

As shown in Figure 9 and more clearly in Figure 11 the pincer arms 36a, 36b are coupled to pincer arm pivot drive means, which in the illustrated embodiment comprises a hydraulic or preferably pneumatic cylinder 39 extending between the pincer arms 36a, 36b but may comprise an electric motor. A tie rod 40 is shown also to extend diagonally between the pincer arms 36a, 36b.

The bearing assemblies 38a, 38b are secured to a transverse launch frame shaft 41, which is mounted at its ends in launch frame bearing assemblies 42a, 42b and is therefore rotatable about its longitudinal axis. The launch frame shaft 41 is coupled to drive means for rotating it, shown in the drawings to comprise a double acting launch cylinder 43, which is suitably a pneumatic cylinder coupled via a bearing 44 to a drive arm 45. The launch frame shaft 41 is coupled via the bearing assemblies 42a, 42b to a traverse means comprising launch frame arms 46a, 46b which are arranged to traverse in a horizontal direction towards and away from the body of the bagplacer 1. More specifically, the illustrated launch frame arms 46a, 46b are mounted for linear movement through runner blocks 47a-d (Figure 10).

The launch frame arms 46a, 46b are coupled to traverse drive means, which may comprise an electric motor but is shown to comprise a pincer traverse hydraulic and preferably pneumatic cylinder 48, which is connected to the launch frame arms 46a, 46b via a bearing 49 and a transverse launch frame bar 50.

In one embodiment of the invention, as depicted in Figure 13 there is shown gripper means 60 a and b mounted on launch frame shaft 41. The gripper means are positioned outwardly from pincer arms 36 a and b and towards the ends of shaft 41. The gripper means comprise arms 62 a and b, each associated with an arm pivot block 64 mounted on shaft 41. The pivot block converts motion from gripper cylinder 66 and a piston/bush arrangement 65 to the arm, so that in use, the gripper arms may pivot towards the pincer arms 36a and b in direction A (Figure 14). Each arm is also provided with a set of terminal gripper fingers 63. The fingers are connected to the arm by gripper brackets 61 a and b.

With reference to Figure 15, the gripper fingers 63 are seen in greater detail. Movement or actuation of the fingers is effected by a pneumatic element 67 accommodated in housing 68. Pneumatic element 67 is typically a double acting pneumatic cylinder coupled directly to the gripper fingers. Movement of the gripper fingers is controlled by a solenoid air valve or the like, the valve being adapted to receive signals from the bagplacer apparatus's central programmable logic controller. In this way it is possible to control the opening and/or closing of the gripper fingers at desired time points.

The gripper fingers, in an open position i.e. when not gripping a bag, are 180° apart and in a closed position, i.e. when gripping a bag are together and abbutting. When the fingers 63 are in the closed position, the pads 70 abut so that they are capable of sandwiching/gripping a bag surface therebetween. The pads 70 can be constructed of a relatively soft and resilient material to ensure a good grip contact with the bag without damaging the bag material itself.

The embodiment of Figures 13-15 is of particular advantage in that the gripper means 60 a and b can be fixedly or releasably connected to the shaft 41. Thus it will be understood that the launch assembly may comprise a pincer arm and gripper combination so that the apparatus can be suitable for filling gusset bags or the gripper means 60 a and b can be removed so that the apparatus may be suitable for filling pillow bags. Moreover, the apparatus can be adapted according to a user's requirements: a user may remove the entire launch assembly and replace it with a different version with or without the gripper elements ;or the user may add the gripper means on to an existing frame.

Turning now to Figure 5, it will be seen that the front end of the bagplacer 1 is located adjacent a side of a bagfiller assembly 51. The bagfiller assembly comprises a feed spout/bag holder assembly 52 which may be of conventional construction, for example. Thus, it suitably comprises a central feed spout 53 and clamp jaws 54a, 54b for clamping both side walls of the bag at its mouth between the clamp jaws 54a, 54b and fixed clamp surfaces 55a, 55b.

Situated beneath the feed spout/bag holder assembly 52 is a conveyor belt 56, on either side of which are located fixed side guides 57a, 57b which serve to position the body of a clamped bag as it is filled and to support it. After a filled bag is undamped, the conveyor belt conveys it to downstream operations.

The further operation of the bagplacer 1 after bag pick-up will now be described. In this respect, it will be recalled that the upper frame 23 lifts a bag 31 from the top of a bag stack situated in the pick-up zone. In the illustrated apparatus, the bag lifting frame 23 with its gripped bag 31 is lifted by the bag lift air cylinder until the limit of the cylinder travel is reached.

The bag 31 is now suspended above the bag stack and drooping of its mouth is restricted by the peripheral suction pads 27a, 27b of the upper frame 23.

The control system then actuates the under frame drive means (air cylinder 35 of the illustrated apparatus) to cause the under frame 32 to pivot upwardly to place its suction pads 33a-c in contact with the bag underside. Suitably, the raised condition is confirmed by a sensor and a timer is started to allow the bag underside to become attached to the under frame suction pads 33a-c. In any event, after a predetermined time, the vacuum in the peripheral suction pads 27a, 27b of the upper frame 23 is released. The upper frame 23 and the under frame 32 are then separated from each other to open the bag mouth. In the illustrated embodiment, the separation is caused by actuation of the bag opening air cylinders 29a, 29b. The pincers 37a, 37b are then moved into the bag mouth under the action of the launch cylinder 43, as shown for example in Figure 8. The pincer arms 36a, 36b are angled towards each other when the pincers 37a, 37b first enter the bag mouth but the pincers 37a, 37b are thereafter separated by pivoting a part of the pincer arms by actuation of the pincer cylinder 39. Suitably, a pincers inserted sensor is provided to determine when the pincers have been inserted into the bag and the pincers should be opened. At the same time as the pincers are opened, the upper frame suction pads and under frame suction pads are deactivated. In the instance of a launch assembly with gripper means 60 a and b, the edges of a gusset bag may be gripped by the gripping fingers.

The pincer traverse cylinder 48 is then activated to move the pincer assembly and gripper means , if present, together with the bag from its previous bag-grip position towards the bagfiller assembly 51. The pincers and gripper means , if present, and bag are stopped in a launch position, suitably confirmed by a sensor.

The pincer arms 36a, 36b and gripper means , if present, are now launched (pivoted upwardly) under the action of the launch cylinder 43 to place the bag into the clamp of the feed spout/bag holder assembly 52. The clamp jaws 54 are energised to grip the bag and the pincer arms 36a, 36b with the pincers 37a, 37b are retracted by downward pivoting and traversing back to the bagplacer 1.

The pincer arms 37a, 37b and gripper means , if present, are thus launched (pivoted up to the feed spout/bag holder assembly 52) over the side guide 57a without the need for the side guide 57a to be opened, as in the case of existing machines. When the bag is initially clamped around the feed spout 53, it drapes over the outside of the side guide 57a but, as the bag is filled, the weight of the contents bring the back within the channel formed between the side guides 57a and 57b. The bag is then dropped on to the conveyor belt and conveyed away for downstream operations.

In some operations of the bagplacer, the traverse action prior to launch may be dispensed with and, in variants of the illustrated bagplacer, the traverse components of the apparatus are not included.

What is important, therefore, is that the pincer arms and gripper means , if present, are capable of being launched over the side guides of the bagfiller assembly. In the operation of the illustrated apparatus, a launched bag must clear the bag stack when clamped, in order to enable the next bag to be picked up from the bag stack without interference. In the case of longer bags, the traverse action from the bag-grip position to the launch position will usually be necessary in order to enable the launched bag to clear the stack.

The traverse action also facilitates clearance of the side guides by the launching pincer arms, since, other things being equal, it enables the length of the pincer arms to be reduced as compared with a corresponding apparatus without traverse action. The use of shorter pincer arms is facilitated by the lifting of the bag stack top to a pick-up zone, since the use of a raised pick-up zone reduces the distance through which the upper frame must travel from the bag stack to the pincer insertion (bag- grip) position.

It will therefore be appreciated that the invention provides a bagplacer having pincer arms adapted to be launched over the top of a side guide of an associated bagfiller assembly. Preferably, after gripping a bag, the pincer arms are traversed towards the bagfiller assembly prior to launch. The complete cycle of the illustrated apparatus is shown in Figure 12, which also includes illustrative timings. Figure 15 illustrates an embodiment of the invention where the launcher frame is also provided with gripping means 60 a and b.

The invention enables either pillow bag or gusset bag filling speed at a comfortable rate to be increased from 720 to 900 bags an hour and includes some simplification of the apparatus, in that the gates hitherto used in the side guides of the bagfiller assembly can be dispensed with.

p40₅17wo

Claims

1. A bagplacer apparatus having pincer arms capable of being launched, i.e. pivoted upwardly, over side guides of a bagfiller assembly.

2. An apparatus according to Claim 1 wherein the pincer arms are capable of being traversed from a bag-grip position to a launch position which is closer to the bagfiller assembly than is the bag-grip position, traverse drive means being provided to move the pincer arms between the bag-grip and launch positions.

3. An apparatus according to Claim 2 wherein the traverse drive means comprises an electric drive or a hydraulic arrangement or a pneumatic arrangement.

4. An apparatus according to either Claim 2 or 3 wherein the pincer arms are each pivotally mounted about a pivot axis for pivoting of their free ends towards and away from each other.

5. An apparatus according to any preceding claim wherein the pincer arms are mounted on a launch member comprising a transverse rod or shaft, which is arranged for rotation with the pincer arms whereby rotation of the launch member causes launching or delaunching of the pincer arms.

6. An apparatus according to Claim 5 which includes the feature of Claim 4 wherein the launch member is arranged for rotation about an axis perpendicular to the pivot axis and the pincer arms are each pivotally mounted about the pivot axis for pivoting of their free ends towards and away from each other.

7. An apparatus according to either of Claims 5 or 6 which further comprises drive means to cause the launch member to rotate.

8. An apparatus according to Claim 7 wherein the drive means comprises an electric drive or a hydraulic arrangement or a pneumatic arrangement.

9. An apparatus according to any of Claims 5-8 wherein the launch member is arranged for longitudinal movement together with the pincer arms, whereby such longitudinal movement affects traverse of the pincer arms from the bag grip position to the launch position, or vice-versa.

10. An apparatus according to any of Claims 5-9 wherein the launch member is rotationally connected to a traverse means which is mounted for linear movement.

11. An apparatus according to Claim 10 wherein the traverse means comprises a pair of arms, each of which is coupled via a bearing to a respective end of the launch member.

12. An apparatus according to either of Claims 10 or 11 wherein the traverse means is mounted for linear movement through runner blocks.

13. An apparatus according to any of Claims 10-12 wherein the drive means is connected to the pincer arms via the launch member.

14. An apparatus according to Claim 13 wherein the drive means is connected to the pincer arms via the launch member and the traverse means.

15. An apparatus according to any of Claims 4-14 further comprising a pair of gripper means pivotally mounted on the launch member.

16. An apparatus according to Claim 15 wherein each gripper means is positioned outwardly of a respective pincer arm.

17. An apparatus according to either Claim 15 or 16 wherein the gripper means comprises a gripper arm, one end of which is provided with a pair of opposed pivoted gripper fingers.

18. An apparatus according to Claim 17 wherein the gripper fingers are arranged so that in a closed position a gripping surface of a first finger abuts a corresponding gripping surface of a second finger whereby in use, a part of a bag may be gripped therebetween.

19. An apparatus according to Claim 18 wherein the gripping surface of the fingers is resiliently deformable or padded.

20. An apparatus according to any of Claims 17-19 wherein one end of the gripper arm is coupled to a pivot block so that the gripper arm is capable of pivoting movement towards the pincer arm.

21. An apparatus according to any of Claims 15-20 wherein the gripper means are fixedly mounted on the launch member.

22. An apparatus according to any of Claims 15-20 wherein the gripper means are detachably mounted on the launch member so that the apparatus can easily be adapted for use with either pillow bags or gusset bags.

23. A kit of parts which includes a launch member, pincer arms and/or gripper means for use with the apparatus of Claims 1 -22.

24. A bagplacer apparatus comprising: a pincer assembly comprising a pair of pincer arms; a rotary launch member to which the pincer arms are pivotally coupled for pincer movement and for rotation therewith; a traverse means to which the launch member is rotationally coupled and which is arranged for linear movement with the launch member and the pincer arms from a first position to a second position; pincer drive means for causing pincer movement of the pincer arms; launch drive means for causing rotation of the launch member; and traverse drive means for causing linear movement of the pincer arms, the launch member and the traverse means.

25. An apparatus according to Claim 24 wherein each of the drive means independently comprises an electric, pneumatic or hydraulic arrangement or an air cylinder.

26. An apparatus according to Claim 24 wherein the drive means are all connected to a common pneumatic or hydraulic system.

27. An apparatus according to any of Claims 24-26 wherein the launch member comprises a transverse shaft rotationally mounted to the traverse means.

28. An apparatus according to any of Claims 24-27 wherein the traverse means comprises a pair of elongate arms, each mounted to a respective end of the transverse shaft.

29. A bag placer apparatus having a bag magazine which is characterised in that, in use, a bag stack is raised to adjust for reduction in bag stack height.

30. An apparatus according to Claim 29 further including a stack height sensing device for monitoring the height of a bag stack, the sensing device being operatively linked to a control system for controlling raising of the stack.

31. An apparatus according to either of Claims 29 or 30 further comprising a magazine empty sensor which is operatively linked to the control system to cause a fresh bag stack to be presented for bag removal.

32. An apparatus according to Claim 31 wherein the sensor is linked to an audio and/or visual alarm so as to alert an operator that the bag stack needs replenishing or replacing.

33. An apparatus according to any of Claims 29-32 wherein the bag stack is raised by incremental amounts.

34. An apparatus according to Claim 33 wherein the bag stack is raised in incremental amounts of from 10 to 60 mm.

35. An apparatus according to Claim 34 wherein the bag stack is raised in incremental amounts of from 10 to 40 mm, preferably 20 to 40 mm.

36. An apparatus according to any of Claims 29-35 comprising a bottom support surface or platform which, in use, supports the bag stack and is upwardly and downwardly moveable by means of a pneumatic, hydraulic or electric drive means.

37. An apparatus according to Claim 36 wherein drive means comprises an air cylinder and the apparatus further comprises a hydraulic speed control check cylinder to control the upward movement of the support surface towards a bag lifting frame.

38. An apparatus according to either of Claims 36 or 37 wherein the support surface moves towards the bag lifting frame in stepwise manner.

39. An apparatus according to any of Claims 36-38 comprising a plurality of compartments each having a respective bottom support surface.

40. An apparatus according to Claim 39 comprising a framework with which the support surfaces are associated and wherein the drive means comprises a lifting member for lifting a selected support surface, the framework and the lifting member being movable relative to each other, whereby the lifting member may be brought into lifting relationship with the selected support surface.

41. An apparatus according to Claim 40 wherein the framework additionally comprises guide means for maintaining the stack in position, the guide means comprising a plurality of posts.

42. A bag-placer apparatus comprising means for supporting a stack of empty bags and operatively associated therewith a means for collecting a bag from the top of the stack, wherein the bag support means is adapted to travel from a first position to a second position closer to the bag collecting means and thereafter to move further towards the bag collecting means.

43. An apparatus according to Claim 42 and further including any one or more of the features of Claims 30-41.

44. A method of presenting a bag stack to a bag lifting frame in a bag magazine, comprising:

(i) placing a stack of empty bags on an upper surface of a bag magazine platform in a first position,

(ii) moving the bag magazine platform towards a bag pick-up frame so as to enable the bag pick-up frame to engage and remove the uppermost bag of the stack to a downstream operation,

(iii) continuing the operation of the pick-up frame whilst raising the magazine platform level so as to approximately compensate for the decrease in stack height,

45. A bagplacer apparatus having a bag pick-up frame provided with suction means characterised in that the suction means is capable in use, of gripping an empty bag at peripheral margins of its upper surface at its mouth such as to control drooping of the mouth.

46. An apparatus according to Claim 45 wherein the suction means is arranged for the gripped peripheral areas of a pick-up bag to be raised relative to an intermediate area.

47. An apparatus according to either Claim 45 or 46 wherein the suction means comprises suction pads.

48. An apparatus according to Claim 47 wherein the suction pads are mounted resiliently by spring loading.

49. An apparatus according to either of Claims 47 or 48 wherein the suction pads for gripping the peripheral areas of a pick-up bag are raised relative to intermediate suction pads.

50. An apparatus according to any of Claims 47-49 wherein suction pads for gripping the marginal areas of a pick-up bag depend a marginally shorter distance from a support frame than those suction pads positioned inwardly therefrom.

51. An apparatus according to Claim 50 wherein the difference in height between the outermost suction pads and their inwardly positioned neighbours is in the region of 2 to 12 mm, preferably 5 to 10 mm.

52. An apparatus according to Claim 51 wherein the difference in height between the outermost suction pads and their inwardly positioned neighbours is in the region of 8 mm.

53. An apparatus according to any of Claims 47-52 wherein the suction pads comprise a front set for gripping the bag at its mouth and a rear set for gripping at a position closer to the closed bag end.

54. An apparatus according to Claim 53 wherein the front set of suction pads comprise at least three pads and normally four pads or more and the rear set at least two.

55. An apparatus according to either Claims 53 or 54 wherein the sets of suction pads are arranged so as to be in substantially parallel with one another.

56. An apparatus according to any of Claims 47-55 further including an underframe which is provided with suction pads.

57. An apparatus according to Claim 56 wherein the under-frame suction pads comprises at least two and normally three pads or more.

58. An apparatus according to either of Claims 56 or 57 wherein suction pads depending from the support frame and under-frame suction pads are aligned, so that in use, they are positioned so as to be substantially directly above one another.

59. An apparatus according to any of Claims 56-58 wherein suction pads positioned inwardly from the peripheral/outermost suction pads on the support frame are directly aligned with at least two under-frame pads.

60. A bagplacer apparatus having a bag pick-up frame provided with three or more suction means for generating suction points, the suction points being arranged so that at least the two outer peripheral suction points are marginally raised relative to suction point(s) positioned inwardly therefrom, so that in use an empty bag is gripped at edges of a bag mouth upper surface so as to correct bag droop.

61. An apparatus according to Claim 60 further including any one or more of the features of Claims 45-59.

62. A method of bag droop correction using a bag-placer apparatus according to Claim 45 or Claim 60.

63. An apparatus according to any of Claims 1-28, which further includes the specific feature(s) recited in one or more of Claims 1, 2-28, 29, 30-41, 42, 43, 44, 45, 46-59 or 60.

64. A bag filled with a product using the apparatus according to any one or more of Claims 1, 24, 29, 42, 45, or 60 and optionally further including any one or more of the features herein before described.

65. A bag filled with a product by the method according the method of Claim 44.

66. A bagplacer apparatus comprising: a pincer assembly comprising a pair of pincer arms; a rotary launch member to which the pincer arms are pivotally coupled for pincer movement and for rotation therewith; a traverse mechanism to which the launch member is rotationally coupled and which is arranged for linear movement with the launch member and the pincer arms from a first position to a second position; pincer drive mechanism coupled to the pincer arms; launch drive mechanism coupled to the launch member; and traverse drive mechanism coupled directly or indirectly to the traverse mechanism.

67. A bag-placer apparatus comprising a support member; and a collecting mechanism operatively associated with the support member, the support member being adapted to travel from a first position to a second position closer to a bag collecting member and thereafter to move further towards the bag collecting member, and in use the support member supporting a stack of empty bags and the collecting member collecting successive top bags of the stack.

68. A bagplacer apparatus having a bag pick-up frame provided with suction nozzles characterised in that the suction nozzles are capable in use, of gripping an empty bag at peripheral margins of its upper surface at its mouth such as to control drooping of the mouth.