GB2074972A

GB2074972A - Bag loader for packaging machine

Info

Publication number: GB2074972A
Application number: GB8014769A
Authority: GB
Original assignee: WR Grace and Co
Current assignee: WR Grace and Co
Priority date: 1980-05-02
Filing date: 1980-05-02
Publication date: 1981-11-11
Also published as: AU6992281A; NL8102118A; SE456985B; FI811332L; IT8121490A0; FI69795C; IT8121490A1; NO811489L; DK152982B; DK192881A; AU538959B2; FI69795B; NZ196887A; DK152982C; GB2074972B; CH652367A5; SE8102595L; DE3116530C2; DE3116530A1; NO155924C

Abstract

A bag loading and sealing device comprises a bag evacuating or gas flushing nozzle 8 and bag spreading members 7 laterally movable towards and away from advanced positions in which they fit within corresponding slots 1c, 1a and 1b of a pusher member 1, and also axially movable towards and away from the position of the neck 3a of a bag 3 in a bag sealing station C. The pusher 1 advances a product article into an opened bag and entrains the bag for movement from the bag loading position to a bag sealing position and then, while the product is held in a precisely predetermined position by means of the pusher member 1, the nozzle 8 and the bag spreading members 7 advance first laterally and then axially into the slots formed in the pusher member, after which the pusher member can be retracted while the bag spreading members draw the bag neck into a substantially flat elongate mouth and the nozzle applies either vacuum or inert flushing gas to the interior of the bag for sealing of the bag using heat sealing means. <IMAGE>

Description

SPECIFICATION Bag loader for packaging machine The present invention relates to a combined bag loader and sealing device, for use in packaging of articles in plastics bags. The term "bag" is intended to denote any open-ended flexible container of bag-like construction, and is not intended to limit the invention to any particular type of bag-like container. The invention is, for example, equally applicable to gussetted bags as to non-gussetted bags. The bags used with the device may for example be multi-layer bags having at least one layer to impart mechanical strength to the bag, and/or at least one layer to impart sealability by thermal welding, and/or at least one gas-impervious barrier layer.

In packaging machines, it is known to provide bag loading devices which take an empty bag and spread the bag open while a product is inserted into the the bag. It is normal for the article to be inserted into the bag by a mechanically actuated pusher which reciprocates between a first, retracted position in which an article can be introduced into the space between the pusher and a bag-loading table, and a second, extended position in which the pusher has advanced such an article onto the loading table and into the open bag.

Once the bag has been loaded in this way, the bag is conventionally advanced either by means of an extended movement of the pusher itself, or by alternative conveying means, to a sealing station where the interior of the bag may undergo atmospheric conditioning, for example evacuation or introduction of a flushing gas or both.

It is an object of the present invention to provide an improved from of bag-loading and sealing device.

Accordingly, the present invention provides a bag loading and sealing device comprising means for holding an open bag ready to receive a product article therein; a pusher member driven for reciprocation along a path between (a) a first position in which it is retracted behind the bagloading station and able to receive a product article between its said first position and the open mouth of a bag held by said bag opening means and (b) a second position in which it has displaced the product article into an open bag on the bag holding means; an atmospheric conditioning nozzle movable in a first direction perpendicular to the direction of movement of the pusher member between its said first and second positions, for movement between a laterally retracted condition in which it is clear of the path of movement of said pusher member and a laterally advanced position in which it is in the path of movement of said pusher member, and also movable in a direction parallel to the said path of movement of the said pusher member for movement of the atmospheric conditioning nozzle between an axially advanced condition in which it is in register with the said second position of the pusher member and an axially retracted condition in which it is retracted behind said second position of the pusher member; and a slot formed in said pusher member and extending therealong, said slot being arranged such that during relative axial movement of said pusher member and said atmospheric conditioning nozzle while said atmospheric conditioning nozzle is in its laterally advanced condition the atmospheric conditioning nozzle can enter through the end of the slot and pass therealong to a position in which it is able to condition the atmosphere within the bag.

With such a device, the loaded bag can be sealed with or without atmospheric conditioning either on a bag loading table or just beyond the end of a bag loading table, the movement of the bag to the sealing and/or atmospheric conditioning station being preferably achieved by means of the pusher member of the bag loader.

Preferably the atmospheric conditioning is evacuation, and the atmospheric conditioning nozzle comprises a nozzle communicated to a source of vacuum. Alternatively, the atmospheric conditioning may be gas flushing, and the nozzle may be communicated with a source of flushing gas. A combination of gas flushing and at least partial evacuation of the bag interior may be employed, if desired.

Conveniently the bag neck may be spread, after loading, to stretch the bag mouth into a substantially flat configuration for subsequent sealing, for example by hot weld sealing. In such an arrangement the bag loading and sealing device may further include bag-spreading members which are capable of being introduced laterally by movement towards one another into lateral recesses of the pusher member, and retracted or extended by axial movement along the direction of the path of movement of the pusher member.In an alternative arrangement, the bag mouth may be spread into a substantially flat configuration while being folded into a gussetted configuration, and in this arrangement there may be four spreading members forming a rectangular array with one pair spaced to either side of the major axis of the rectangle and one of the bars of each pair to one side of the minor axis and the other bar of each pair to the other side of said minor axis, and a pair of bag-folding members may be provided so as to be movable towards and away from one another along said major axis of the rectangle defined by the said two pairs of spreading members. Suitable recesses for the spreading members and folding members may be provided in the pusher, so as to allow lateral insertion into and retraction from the pusher.

The device may be adapted to operate such that the pusher retracts before expansion of the spreading members, where provided.

Alternatively, the pusher member may begin to retract at the same time as the spreading members begin their separating movement. It is advantageous for the pusher member to retract before the operation of the spreading members, and at least before the atmospheric conditioning step, so that the pusher member can retract to its above-mentioned first position to allow positioning of a further product article and of a further bag for loading while the first-mentioned loaded bag is being spread and atmospherically conditioned.

Means may be provided for adjusting the stroke of the pusher member so that the pusher member always displaces the product article to the closed end of a bag at the loading station, thereby allowing the device to be adjusted to accommodate different bag lengths and product article dimenions while giving absolute accuracy of positioning of the atmospheric conditioning nozzle and the spreading members, where provided.

In order that the present invention may more readily be understood, the following description is given, merely by way of example, of one embodiment of a bag loading device in accordance with the present invention. This device is illustrated schematically in the accompanying drawings in which:: FIGURE 1 is a schematic perspective showing a bag spread at the loading station and the pusher member about to introduce a product article into the spread bag; FIGURE 2 is a schematic perspective showing the position of the various elements of Figure 1 after the pusher member has advanced the product article into the bag; FIGURE 3 is a schematic perspective showing the same position of the bag and pusher member but with the atmospheric conditioning nozzle and the spreading members advanced into a position in which they are ready to be moved axially into the pusher member; FIGURE 4 is a schematic perspective showing the position of the atmospheric conditioning nozzle and the spreading members after they have been advanced into their recesses in the pusher member;; FIGURE 5 is a schematic perspective showing the subsequent configuration of the bag when the bag spreading members have spread the mouth of the bag into a substantially flat configuration leaving the atmospheric manipulation nozzle in position between the upper and lower layers of the bag mouth, while the pusher member has begun retracting movement prior to loading of the next product article into a bag; and FIGURE 6 is a schematic elevation illustrating a bag gusset folding action in an alternative embodiment of bag loading and sealing device.

Referring now to Figure 1 ,there can be seen the bag 3 spread on two bag holding members 4 which hold the mouth of the bag open in a rectangular configuration ready for the introduction of a product article 2 by means of leftward movement of a pusher member 1. Above the bag is an atmospheric conditioning nozzle 8, in this case a flat nozzle communicated to a source of vacuum to extract air from within the bag, prior to the sealing operation, so as to present a tidy vacuum pack of the bag 3 on the rectangular parallelepiped-shaped article 2.

Alongside the bag 3 are two flat spreading members which comprise support bars of cylindrical form and end plates 7 defining flat bagengaging members which, during spreading movement of the bag-spreading members 7 by movement of the members along the common axis of their cylindrical portions 6, spread the bag mouth into a substantially flat configuration ready for sealing.

To the left of the bag loading table 5 is a roller conveyor 10 on which the sealed and evacuated package rests prior to delivery, after conclusion of the operation of the bag loading device.

Figure 2 shows the elements of Figure 1 at the end of the bag loading phase, when the pusher member 1 has advanced the product 2 initially into the opened bag 3 at the bag loading station B and then beyond, entraining the bag for movement off the bag holding plates 4a and onto the roller conveyor 10 at the bag sealing and atmospheric conditioning station C.

When the pusher member 1 arrives in the position illustrated in Figure 2, the two bag holding members 4 are still in their Figure 1 positions and so also are the atmospheric conditioning nozzle 8 and the two bag-spreading members 7. Meanwhile, the bag has arrived in a position where its neck 3a is still held so as to define an open mouth (by the action of the pusher member inside the bag), and is in line with the sealing members, in this case upper and lower horizontal sealing bars 14 and 1 5 (see Figure 5).

In the Figure 3 position, the pusher 1 , the product article 2 and the bag 3 are all in the same position in which they were illustrated in Figure 2, but the two bag-spreading plates 7 on their respective cylindrical actuating rods 6 have moved together along the directions of oppositely directed collinear arrows 11 a, 1 b, while the flat atmospheric conditioning nozzle 8 has descended by axial movement of its actuating tube 8a downwardly along the direction of arrow 1 C. In this configuration, the two bag spreading plates 7 and the atmospheric conditioning nozzle 8 are exactly in line with corresponding recesses 1 a, 1 b, and 1 C of the pusher 1. The precise geometry and the function of these recesses will be described below.

Between the Figure 3 position and the Figure 4 position, the two bag spreading plates 7 and the atmospheric conditioning nozzle 8 have advanced along parallel directions, illustrated by arrows 1 2a, 1 2b and 1 2c, which extend along the direction of reciprocation of the pusher member 1. These two bag-spreading members and the atmospheric conditioning nozzle have arrived at a final position in which they are received in the respective recesses 1 a, 1 b and 1 c. At this stage, the function of the pusher member is complete, and the atmospheric conditioning nozzle 8 as well as the two bag spreading members 7 have been introduced into the now open mouth defined by bag neck 3a.

In order to enhance the rate of cycling of the bag loading and closing device in accordance with the present invention, the pusher member 1 is now retreating past the inserted bag spreading members 7 and atmospheric conditioning nozzle 8, to arrive at a configuration shown in Figure 5 where the pusher member is still undergoing its retreating movement towards the product infeed station A and is, at the instant depicted in Figure 5, passing through the bag loading station B.

Meanwhile, the bag 3 with the product article 2 therein is still sitting on the roller conveyor 10 but now the previously open neck of the bag has been flattened into a substantially horizontal, elongate, nearly closed mouth configuration with the fiat atmospheric conditioning nozzle 8 near the centre and the similarly flat bag spreading members 7 to either side of the nozzle 8. In this position, the bag neck 3a is almost ready for the evacuation process to begin; this, however, requires tensioning of the bag mouth which is achieved by withdrawing the two bag spreading members 7 away from one another by movement of their supporting rods 6 along the collinear opposed directions depicted by arrows 1 3a and 1 3b, until the tension in the bag mouth is sufficient to allow cessation of further movement of the spreading members.

Arresting of the spreading members in their final position may either be by virtue of the bag tension actuating a limit switch of some kind, or simply by setting the apparatus to spread the two edges of the bag neck to a given spacing commensurate with the size of bag being handled.

Naturally, the reliance on bag neck tension has the advantage that when the bag size is changed, no adjustment of the lateral travel of the bag spreading members 7 is required because the tension in the bag neck will automatically stop the separating movement of the bag-spreading members when they have carried out their intended purpose.

Figure 5 also shows upper and lower clamping end sealing bars 14 and 15, respectively, which have resilient inserts (not shown) extending therealong on the co-operating clamping face such that the flat atmospheric conditioning nozzle and the two flat bag-spreading members can be received between the two bars 14 and 1 5 by virtue of the compressibility of the resilient inserts.

Where there is no intervening bag-spreading member 7 or atmospheric conditioning nozzle 8, the resilient inserts in the clamping bars 14 and 1 5 come together to hold the bag mouth closed.

At the completion of the arrival of the Figure 5 configuration, vacuum is applied to the atmospheric conditioning nozzle by way of its hollow actuation tube 8a, and thus the air within the bag 3 is extracted before finally a heat impulse is applied at the areas of contact between the upper and lower bars 14 and 1 5 and the superposed layers of the bag neck defining the mouth illustrated in Figure 5.

The sealing operation may be performed in two stages such that before removal of the two bag spreading members 7 and of the atmospheric manipulation nozzle 8 from the bag mouth the areas of the flat mouth so far in contact are sealed after which the nozzle 8 and plates 7 may be withdrawn to allow the last areas of the superposed bag mouth layers to be pressed into contact and sealed. More preferably the sealing action is delayed until the nozzle 8 and plates 7 have been withdrawn (after evacuation) and sealing then takes place simultaneously along the whole of the bag neck.

The two bag spreading members 7 and the nozzle 8 are withdrawn initially in an axially retreating movement (i.e. in directions opposite to the three arrows 1 2a, 1 2b and 1 2c of Figure 4) and then are separated by lateral retreating movement along directions opposite to those illustrated by the arrows 11 a, 1 b and 1 C so that the article advancing path is left clear for the next product article 2 to pass from the article infeed station A to the roller conveyor 10 at the sealing station C without striking the two bag spreading members 7 or the nozzle 8.

While the evacuation and sealing step is underway in Figure 5, the pusher member 1 completes its retreating movement to arrive behind the article infeed station ready for engagement of the next product article and for driving that article forwardly towards the bag holding members 4 which will be now have had a fresh bag spread thereon in the Figure 1 configuration.

If desired, more than one atmospheric conditioning nozzle may be used. Either this may involve two or more separate nozzles 8 symmetrically disposed with respect to the line of action of the movement of the pusher member 1 (i.e. symmetrically with respect to the axis of the actuating rod 9 of the pusher 1) or the two bag spreading members 7 may be hollow so that they also carry out some atmospheric conditioning function. For example, the nozzle 8 may serve to extract air from within the bag 3 while a flushing gas is introduced into the bag through the hollow bag spreading members 7.Another possible arrangement is one in which the nozzle 8 serves as a flushing gas injection nozzle to provide for the situation where the interior of the package is not to be under vacuum but is to be in a conditioning environment consisting of a gas (for example nitrogen) which is chemically inert to the product article in the package.

Various configurations can be envisaged for the two side slots 1 a and 1 b of the pusher 1, provided in each case they allow the bag spreading members to enter the pusher 1 from the rear, to leave the pusher 1 through its lateral area during the bag spreading action, and to be clear of obstructing the pusher as the pusher 1 is retracted while the bag mouth is held in the Figure 5 configuration by means of the two bag-spreading members 7.

The upper slot 1 C of the pusher 1 must be capable of allowing the atmospheric conditioning nozzle 8 to enter the pusher member from behind, and to leave the pusher member from the front as the pusher is withdrawn relative to the stationary now inserted atmospheric manipulation nozzle in the Figure 4 situation. This slot is upwardly open in order to allow for holding of the nozzle 8 by means of its actuation tube 8a during movement of the atmospheric conditioning nozzle along the full length of the slot 1 c.

As shown in Figures 1 to 5, the three slots 1 a, 1b and 1 c each extend along the full length of the pusher member and, for the sake of convenience, the bottom of the lateral grooves 1 a and 1 b is cut away. This allows the same pusher member to be used with the two bag spreading members 7 and with a gusset-folding system described below with reference to Figure 6.

Although not mentioned above the various actuation members for the moving components, in this case the rod 9 for the pusher member 1, the rods 6 for the two bag spreading members 7, and the actuation tube 8a for the atmospheric conditioning nozzle 8, are driven by suitable rams or other drive mechanisms. Where these actuation members are driven by rams, the rods/tubes 6, 8a and 9 may themselves be the piston rods of the rams.

The timing of the movement of the pusher 1 in relation to the actuation of the bag spreading members 7 and the atmospheric conditioning nozzle 8 can be varied, although in practice it is preferred for the pusher member 1 to be retracted before the bag spreading members 8 have completed their bag spreading action, thereby ensuring that the bag neck 3a does not drag on the upper edges of the pusher 1, with the risk of tearing of the bag.The ideal situation is to have the pusher member retracting as early as possible in order to initiate the next bag loading cycle as soon as possible, but making sure that the pusher member 1 remains in position at least until the two bag spreading members 7 and the atmospheric conditioning nozzle 8 have completed axial advancing travel from the Figure 3 position to the Figure 4 position in order to ensure that the bag neck 3a is correctly positioned in relation to the clamping and sealing members 14 and 1 5 before the pusher member is withdrawn.

However, if desired, retraction of the pusher member may start just before the completion of axial advancing movement of the bag-spreading members and the atmospheric conditioning nozzle along the lines of action of arrows 1 2a, 1 2b and 1 2c from the Figure 3 position to the Figure 4 position.

Finally, the sealed bag 3 with its product 2 therein is despatched from the sealing station either by driving the rollers 10 in the case of an active roller conveyor, or by some other transport mechanism in the case of a passive roller conveyor or other conveying system.

Although it is not essential to the present invention that the two bag holding members 4 retract well clear of the path of movement of the pusher member 1 after they have completed the bag-holding function illustrated in Figure 1, such separating movement may be an advantage where it is desirable to be able to change the size of the pusher member, for example to accommodate different bag sizes and product article widths.

Furthermore, although in the particular embodiment described above the sealing station C is separate from the bag loading station B in that the pusher member 1 drives the bag off the bag holding members 4a, it is alternatively possible to arrange for advancing movement of the pusher member to stop once the article 2 is in the open bag 3 and then to separate the bag from the holding member 4a by retracting the holding member 4a while the stationary pusher member 1 prevents the bag 3 and article 2 from retreating.

Although the typical embodiment illustrated in Figures 1 to 5 uses a single atmospheric conditioning nozzle 8 as well as two bagspreading members 7, it is of course conceivable for the bag-spreading members to be omitted and for reliance to be placed on the fact that the pressing action of the two bars 14 and 1 5 shown in Figure 5 will be sufficient to flatten the bag mouth.

The supply of bags to the bag loading station B may be by any conventional form, for example a chain of imbricated tapered bags or a stack of wicketted bags. Bag opening may be automatically performed by inflation air jets, or the bags may be individually placed on the bag holding members 4a, if required; this latter step would tend to slow down the cycling of the device.

Prodyct articles 2 will be fed to the product infeed station A by any suitable conveying means, or by hand.

The length of the pusher member 1 is preferably always greater than the difference between the bag length and the product length, so that the rearmost part of the pusher member (i.e.

the end nearer its actuating rod 9) is always outside the bag. For this reason, where a plurality of different bag lengths and product lengths is required, the pusher member 1 will be arranged such that it has a fixed length which is greater than the greatest anticipated difference between the bag length and the product length.

The cross-section of the pusher member is wide enough to define the slots into which the bag-spreading members are received.

The width of the pusher member 1 will be smaller than the width of the product so that the pusher member can always push the product article into the bag without the need for the bag size to be large enough to accommodate a pusher which is larger than the article. The purpose of this is to ensure that the limiting factor on the smallest possible bag size is the girth of the product article and not that of the pusher member.

The advantages of the machine illustrated in the drawings over bag loaders and evacuating machines known in the prior art include the fact that because the pusher member 1 can always execute a given stroke without fear of fouling the nozzle 8 or bag-spreading bars 7, the rear face of the product article 2 is always positioned in a precisely known position such that the atmospheric conditioning nozzle 8 can always be brought into a position at its optimum spacing from the rear of the product article 2 when the nozzle 8 has moved to the Figure 4 position. In this way there will be no difficulty in registering the location of the closing seal, formed by the bars 14 and 1 5, with respect to either the rim of the bag mouth or the position of the atmospheric conditioning nozzle 8 in the Figure 5 configuration.This gives not only a much more reliable positioning for the seal but also a much more effective use of the atmospheric conditioning resources because of the small volume of the bag interior behind the line of the clamping action of the bars 14 and 1 5 (i.e. to the left of those bars as viewed in Figure 5). In the case of vacuumising to establish a vacuum atmosphere inside the bag, or in the case of atmospheric conditioning by inert gas flushing, the vacuumised volume resulting from the optimum positioning of the product article 2 with respect to the bars 14 and 1 5 is an important economic factor.

The device illustrated in the drawings is particularly suitable for packaging articles such as cheese blocks which may weigh as much as 20 Kg. Other bulky product articles can also be particularly conveniently handled using this device.

If a gussett fold formation is to be formed at the mouth of the bag, upon sealing, then the arrangement will be modified slightly and the view, looking along the direction of the line of action of the actuating rod 9 for the pusher (but omitting all components apart from the atmospheric conditioning nozzle and the bag mouth spreading and folding members) is shown in Figure 6 as comprising an upper pair of bag spreading bars 1 6a and 1 6b disposed symmetrically to either side of the centre 21 of the suction nozzle 8, and a lower pair of corresponding bag-spreading bars 1 7a and 1 7b, again disposed to either side of the centre 21 of the nozzle 8, and directly below the two bars 1 6a and 1 6b of the first pair.The bars 1 6a, 1 6b, 17a and 1 7b thus define the corners of a rectangle having a horizontal major axis and a vertical minor axis.

A pair of bag folding members 1 8a and 1 8b is positioned at a level mid-way between the upper and lower pairs of members 1 6a, 1 6b and 1 7a, 1 7b, (i.e. on the major axis of the rectangle) and they are driven in such a way that they are always symmetrically disposed to either side of the centre 21 of the nozzle 8.

The illustration of Figure 6 shows the movement of the various bag-spreading members partway through their bag spreading action.

Initially, the bag-spreading bars of the upper and lower pairs 1 6a, 1 6b, 1 7a, 17b are all closer to one another than as shown in Figure 6, and the bag folding members 1 8a and 186 are further apart, at a spacing which is greater than the spacing between the bars 1 6a and 1 6b on the one hand and 1 7a and 176 on the other hand.

The two folding members 1 8a and 186 move inwardly along the directions of arrows 20a and 20b, respectively, as the upper and lower members 1 6a, 1 6b and 1 7a, 17b move away from one another along the direction of the arrows 1 9a, 1 91', and 1 9c, 1 9d, respectively.

When eventually the bag-spreading bars 1 6 and 1 7 are at their maximum spacing and the folding bars 1 8a and 186 are at their minimum spacing, the bag mouth 3a will have been fully stretched and folded into a gussetted configuration, ready for sealing.

In the illustration of Figure 6, the vertical spacing between the upper and lower pairs of bars 1 6a, 1 61', on the one hand and 1 7a, 1 7b on the other hand is exaggerated, in order to illustrate more clearly the way in which the gusset folding operation proceeds. In practice, however, the upper and lower bag-spreading bars will be at a smaller vertical spacing.

When the gusset folding action is complete, the sealing bars 14 and 1 5 of Figure 5 close together to press the upper and lower superposed layers of the bag mouth 3a into contact with one another on the six spreading bars 1 6a, 1 61', 1 7a, 1 7b and 1 8a, 186 on the nozzle 8.

Although the closing of the bag in the above described embodiment is by way of a hot-weld seal, some other closing action (usually without the bag spreading member 7) may be used; for example the bag may be clipped after retraction of an atmospheric conditioning nozzle.

Claims

1. A bag loading and sealing device comprising means for holding an open bag ready to receive a product article therein; a pusher member driven for reciprocation along a path between (a) a first position in which it is retracted behind the bag loading station and able to receive a product article between its said first position and the open mouth of a bag held by said bag opening means and (b) a second position in which it has displaced the product article into an open bag on the bag holding means; an atmospheric conditioning nozzle movable in a first direction perpendicular to the direction of movement of the pusher member between its said first and second positions, for movement between a laterally retracted condition in which it is clear of the path of movement of said pusher member and a laterally advanced position in which it is in the path of movement of said pusher member, and also movable in a direction parallel to the said path of movement of the said pusher member for movement of the atmospheric conditioning nozzle between an axially advanced condition in which it is in register with the said second position of the pusher member and an axially retracted condition in which it is retracted behind said second position of the pusher member; and a slot formed in said pusher member and extending therealong, said slot being arranged such that during relative axial movement of said pusher member and said atmospheric conditioning nozzle while said atmospheric conditioning nozzle is in its laterally advanced condition the atmospheric conditioning nozzle can enter through the end of the slot and pass therealong to a position in which it is able to condition the atmosphere within the bag.

2. A device according to Claim 1, wherein said atmospheric conditioning nozzle is connected to a support member extending parallel to the direction of movement of said atmospheric conditioning nozzle between its said laterally retracted and laterally advanced conditions, and wherein said slot in the pusher member opens into a lateral face of the pusher member to allow said support member of the atmospheric conditioning nozzle to pass through said open face of the pusher member during relative axial movement of said atmospheric conditioning nozzle and said pusher member.

3. A device according to Claim 1 or Claim 2, and including means for sealing the neck of a said bag when said pusher member is in its second position and has pushed a product article into a bag and the bag has been disengaged from said holding means, said sealing means comprising sealing members movable towards and away from one another in a direction laterally of said path of movement of said pusher member.

4. A device according to Claim 3, wherein said second position of the pusher member is one in which said pusher member has advanced beyond the bag holding means to remove a bag from said holding means.

5. A device according to Claim 3 or Claim 4, wherein said sealing members comprise parallel sealing bars for heat-sealing the neck of a said bag, and for pressing the neck of said bag into a substantially flat configuration enclosing said atmospheric conditioning nozzle when said atmospheric conditioning nozzle is in its said axially advanced condition and said pusher member is remote from its said second position.

6. A device according to Claim 5, and further including bag-spreading members positioned symmetrically about the path of movement of said pusher member between its said first and second positions, and driven for movement towards and away from one another between laterally advanced conditions in which they are in register with said path of movement of the pusher member in its said second position and a laterally retracted condition in which they are clear of said path of movement of said pusher member, and also for movement in a direction parallel to the direction of movement of said pusher member between an axially advanced condition inside the neck of a said bag surrounding the pusher member at said second position of said pusher member, and an axially retracted condition clear of a said bag neck; and further including slots in said pusher member to accommodate movement of said bag-spreading members between their said laterally retracted conditions and their said laterally advanced conditions.

7. A device according to Claim 6, wherein said slots to receive the bag-spreading members are formed in opposed sides of said pusher member and said slot to receive said atmospheric conditioning nozzle is formed in the top of said pusher member.

8. A device according to any one of the preceding claims, wherein said atmospheric conditioning nozzle is driven for a cycle of movements comprising firstly laterally advancing movement between its said laterally retracted condition and its said laterally advanced condition, secondly axial movement between its said axially retracted condition and its said axially advanced condition, thirdly lateral retreating movement between its said laterally advanced condition and its said laterally retracted condition, and fourthly axially retreating movement between its said axially advanced condition and its said axially retracted condition.

9. A device according to Claim 8 when appendant to Claim 6 or Claim 7, wherein said bag-spreading members are driven for a cycle of movements comprising; firstly, simultaneously with said laterally advancing movement of atmospheric conditioning nozzle, laterally advancing movement between said laterally retracted condition and said laterally advanced condition; secondly, simultaneously with said axially advancing movement of the atmospheric conditioning nozzle, axially advancing movement between said axially retracted condition and said axially advanced condition; thirdly, simultaneously with said laterally retreating movement of said atmospheric conditioning nozzle, laterally retreating movement between said laterally advanced conditions and said laterally retracted conditions; and fourthly, simultaneously with said axially retreating movement of the atmospheric conditioning nozzle, axially retreating movement between said axially advanced condition and said axially retracted condition.

10. A device according to any one of the preceding claims, wherein said atmospheric conditioning nozzle is a flushing gas injection nozzle.

1 A device according to any one of Claims 1 to 9, wherein said atmospheric conditioning nozzle is a vacuum nozzle.

12. A device according to Claim 10 or Claim 11, where appendant to any one of Claims 6, 7 and 9, wherein said bag-spreading members are hollow and themselves form further atmospheric conditioning nozzles.

13. A package formed using the bag loading and sealing device of claim 12.

13. A device according to any one of Claims 6, 7, 9 and 12, wherein there are four of said bagspreading members arranged in a rectangular configuration and arranged for movement in pairs towards and away from one another, and further including bag folding members movable in opposition to associated ones of said mentioned bag-spreading members towards and away from one another along the major axis of said rectangle formed by the bag-spreading members.

14. A bag loading and sealing device constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

1 5. A package formed using the bag loading and sealing device of Claim

14.

New claims or amendments to claims filed on 23/4/81 Superseded claims 1-15 New or amended claims:

1. A bag loading and sealing device comprising means for holding an open bag ready to receive a product article therein; a pusher member driven for reciprocation along a path between (a) a first position in which it is retracted behind the bag loading station and able to receive a product article between its said first position and the open mouth of a bag held by the bag-holding means and (b) a second position in which it has displaced the product article into an open bag on the bagholding means; bag-spreading members positioned symmetrically about the path of movement of the pusher member between its said first and second positions, and driven for movement towards and away from one another between laterally advanced conditions in which they are in register with said path of movement of the pusher member in its second position and a laterally retracted condition in which they are clear of the path of movement of the pusher member, and also for movement in a direction parallel to the direction of movement of the pusher member between an axially advanced condition inside the neck of a said bag surrounding the pusher member at the second position of the pusher member, and an axially retracted condition clear of a said bag neck; slots in said pusher member to accommodate movement of the bag-spreading members between their laterally retracted conditions and their laterally advanced conditions; parallel sealing bars for heat-sealing the neck of a said bag, and for pressing the neck of the bag into a substantially flat configuration enclosing the bag-spreading members when said bag-spreading members are in their axially advanced condition and the pusher member is remote from its second position; and atmospheric conditioning means effective to apply suction and/or to introduce a flushing gas to the interior of a bag held on said spreading members.

2. A device according to claim 1 , wherein said atmospheric conditioning means comprise an atmospheric conditioning nozzle movable in a first direction perpendicular to the direction of movement of the pusher member between its said first and second positions, for movement between a laterally retracted condition in which it is clear of the path of movement of the pusher member and a laterally advanced position in which it is in the path of movement of the pusher member, and also movable in a direction parallel to the said path of movement of the pusher member for movement of the atmospheric conditioning nozzle between an axially advanced condition in which it is in register with the second position of the pusher member and an axially retracted condition in which it is retracted behind the second position of the pusher member and the pusher member includes a further slot extending therealong, and arranged such that during relative axial movement of the pusher member and said atmospheric conditioning nozzle while the atmospheric conditioning nozzle is in its laterally advanced condition the atmospheric conditioning nozzle can enter through the end of the further slot and pass therealong to a position in which it is able to condition the atmosphere within the bag.

3. A device according to claim 2, wherein said atmospheric conditioning nozzle is connected to a support member extending parallel to the direction of movement of said atmospheric conditioning nozzle between its laterally retracted and laterally advanced conditions, and wherein the further slot in the pusher member opens into a lateral face of the pusher member to allow the support member of the atmospheric conditioning nozzle to pass through the open face of the pusher member during relative axial movement of the atmospheric conditioning nozzle and the pusher member.

4. A device according to claim 2 or 3, wherein the first-mentioned slots to receive the bagspreading members are formed in opposed sides of the pusher member and the further slot to receive said atmospheric conditioning nozzle is formed in the top of the pusher member.

5. A device according to any one of claims 2, 3 and 4, wherein the atmospheric conditioning nozzle is driven for a cycle of movements comprising firstly a laterally advancing movement between its laterally retracted condition and its laterally advanced condition, secondly an axial movement between its axially retracted condition and its axially advanced condition, thirdly a lateral retreating movement between its laterally advanced condition and its laterally retracted condition, and fourthly an axially retreating movement between its axially advanced condition and its axially retracted conditon.

6. A device according to claim 5, wherein the bag-spreading members are driven for a cycle of movements comprising firstly, simultaneously with the laterally advancing movement of the atmospheric conditioning nozzle, laterally advancing movements between the laterally retracted condition and the laterally advanced condition; secondly, simultaneously with the axially advancing movement of the atmospheric conditioning nozzle, axially advancing movements between the axially retracted condition and the axially advanced condition: thirdly, simultaneously with the laterally retreating movement of the atmospheric conditioning nozzle, laterally retreating movements between the laterally advanced conditions and the laterally retracted conditions; and fourthly, simultaneously with the axially retreating movement of the atmospheric conditioning nozzle, axially retreating movements between the axially advanced condition and the axially retracted condition.

7. A device according to any one of claims 1 to 6, wherein said second position of the pusher member is one in which said pusher member has advanced beyond the bag holding-means to remove a bag from the holding-means.

8. A device according to any one of the preceding claims, wherein the atmospheric conditioning means comprise flushing gas injection means.

9. A device according to any one of claims 1 to 7, wherein the atmospheric conditioning means comprise means for evacuating a said bag.

10. A device according to any one of claims 1 to 9, wherein the bag-spreading members are hollow and themselves form part of the atmospheric conditioning means.

11. 1 1. A device according to any one of the preceding claims, wherein there are four of the bag-spreading members arranged in a rectangular configuration and arranged for movement in pairs towards and away from one another, and further including bag-folding members movable in opposition to associated ones of the bagspreading members towards and away from one another along the major axis of the rectangle formed by the bag-spreading members.

12. A bag loading and sealing device constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.