GB2080179A - Apparatus for separating and loading bags of a chain of side- sealed packaging bags - Google Patents

Abstract

Apparatus for separating bags 8a, 8b, 8c from a roll of side-sealed plastic bags in a pre-perforated continuous chain comprise a first bag holding assembly 15 for holding the leading bag 8a adjacent the perforation line dividing that bag from the next successive bag 8b, which is adapted to be held by a second bag-holding assembly 10. The first bag holding assembly 15 is pivotal in operation so that as it is driven away from the second bag-holding assembly 10 more tension is placed on one margin of the bag chain than the other to provoke rupture of the perforation line at that one end. Further separating movement of the first bag-holding mechanism away from the second bag-holding assembly 10 completes separation along the perforation line and assists in advancing the first bag towards a loading station. <IMAGE>

Description

SPECIFICATION Method and apparatus for separating and loading bags of a chain of side-sealed packaging bags The present invention relates to apparatus for separating and loading bags from a supply chain of laterally facing side-sealed packaging bags joined along their side seals by lines of predetermined weakness.

It is known to load product articles into packaging containers such as flexible bags of heat-shrinkable film material by supplying bags to the bag loader, for example in the form of a continuous chain of discrete bags carried releasably on adhesively-coated support tapes, and to locate an article to be packaged at the loading station by feeding it forwardly on a conveyor belt into a guide from which the article is propelled into the leading bag of the chain, after opening of the bag by for example an inflation air jet.

The above-mentioned form of bag loader accepts the bags in shingled or imbricated configuration and it is then left up to either the operator or some manual article-advancing means, to remove the top loaded bag from the imbricated bag chain before the next successive bag can be inflated and loaded.

Supplying the bags in imbricated configuration in a taped chain offers considerable advantages over manual supply of the bags one at a time to the loading equipment, but the bags, when imbricated, may have a tendency to fold over during the feeding to the loading station, and consequently carefully designed and operated bag handling equipment is needed in order to ensure that the bags are supplied in an unfolded configuration such that the pneumatic bag-opening inflation system is capable of operating reliably on the top bag at the time of loading.

According to one aspect of the present invention we provide apparatus for separating and loading bags from a chain of side-sealed laterally extending packaging bags, comprising downstream bag-holding means adapted to engage a first bag of the chain to one side of a line of predetermined weakness separating two bags of the chain when said first bag is in a first position; upstream bag-holding means adapted to engage a second, adjacent bag of said chain at the other side of said line of predetermined weakness when said second bag is in a second position; means for separating the downstream and upstream bag-holding means by relative movement in a direction so as to separate the said first bag from the said second bag of the chain by applying a separating tension across the said line of predetermined weakness such that the tension at one end of said line is greater than at the other; means operative to control said upstream bag-holding means to release said second bag after completion of separation of the first bag therefrom and to drive said upstream bag-holding means along the bag chain to clamp a third bag of said chain adjacent the line of predetermined weakness separating that third bag from the immediately preceding bag of the chain; means for advancing the said first bag, after separation, to a bagloading station; and means for opening said first bag at said bag-loading station.

The apparatus in accordance with the present invention has the advantage over a taped bag loader that the bags may be supplied to the loader in the form of a chain of laterally extending bags at least partially joined together by side seals of the bag walls which side seals extend transversely of the chain, the mouth ends of the various bags being arranged at one margin of the chain with the mouths facing laterally at that margin, and the closed ends of the bags being arranged along the opposite margin of the chain. Such a bag supply chain is able to be advanced under tension to the bag loading station and consequently there is no risk of folding of the bags due to their being loosely shingled on an adhesively-coated support structure.Moreover, the positive action of separating the leading bag from the next successive bag of the chain while holding the next successive bag ready for subsequent separation ensures that, before the article is loaded in the bag, the bags are separated from one another. This has the advantage that in the albeit unlikely event of the bag-separating action causing damage to the bag being separated, it is readily possible either for an operator to remove that bag and to delay insertion of the next successive article, or for suitable automatic monitoring to be effective to carry out the same function.

Preferably the lines of predetermined weakness are lines which are already pre-perforated and possibly even partially separated and consequently it is possible to ensure that by placing one margin of the bag chain under higher tension than the other margin the separation of the first bag from the second bag of the chain is positive and reliable as a means of provoking rupture along the intended line of separation between bags.

Another aspect of the present invention provides a method of separating and loading side-sealed bags of a continuous chain of laterally extending packaging bags joined by lines of predetermined weakness between the side seals of adjacent ones of said bags, comprising: advancing said chain of bags to a bag-separating location; holding a first one of said bags adjacent its side seal and to one side of said line of predetermined weakness between said first bag and a next successive, second bag; holding said next successive second bag adjacent its side seal at the other side of said line of predetermined weakness; pulling said first bag forwardly along a direction away from said next successive second bag while imposing greater tension on one end of said line of predetermined weakness than on the other end of said line of predetermined weakness; continuing said separating movement of said first bag away from said second bag until completion of rupture along the full length of said line of predetermined weakness to achieve total separation of said first bag from said second bag; carrying said first bag forwardly to a bag-loading station; at or before said bag loading station, opening said first bag for loading of an article thereinto; simultaneously with said advance of the first bag to said bag-loading station gripping a third bag adjacent its side seal to one side of said line of predetermined weakness between that third bag and the next preceding bag; and finally drawing said gripped third bag forward to bring the said line of predetermined weakness between the third bag and the next preceding bag into registration with the previous position of the line of predetermined weakness between said first and second bags.

In order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings in which: Figure 1 is a side elevational view in schematic form of an apparatus in accordance with the present invention; Figure 2 is a top plan view of the apparatus illustrated in Fig. 1; Figures 3a, 3b and 3c are large scale sectional views taken on the line Ill-Ill of Fig.

1, to show the operation of the bag pincer mechanism; and Figure 4 is a small scale sectional view taken on the line IV-IV of Fig. 1 to show the operation of the third bag clamping means.

The apparatus schematically illustrated in Figs. 1 and 2 comprises a supply roll 1 of pre-perforated side-sealed bag material in the form of a continuous chain of bags having the "mouth ends" of the various bags arranged along one margin of the chain (at the end 1 a of the supply roll in Fig. 2) and the "closed ends" of the bags at the other margin (corresponding to the end 1 b of the supply roll in Fig. 2).

From the supply roll 1, the bag material passes over a guide 2 and onwardly to a bagseparating station 3.

At the bag-separating station 3 a pull on the bag chain is exerted along the line of predetermined weakness defined by a perforation line between the trailing side of the first bag of the chain and the leading side of the second bag of the chain. In doing so, the bagseparating mechanism exerts more tension at the end of the line of predetermined weakness near the "closed ends" of the two bags than it does on the end of the line of predetermined weakness corresponding to the mouth ends of the two bags. indeed, one possibility is for there to be substantially no tension at the "mouth end" of the line of weakness and for the bag-separating tension to be concentrated at the "closed end" of the line of predetermined weakness.

From the bag separating station 3 the separated first bag is moved laterally to the bag loading station 4 in line with an article pushing member 5. The individual articles to be loaded into the bags by operation of the pusher 5 are fed to the loading station 4 by means of an article-advancing conveyor of the type described and claimed in our copending British Patent Application No.

(Publication No. ) a copy of which is filed herewith. Such conveyor has a series of laterally extending pockets the width of which can be adjusted.

The articles are picked up in the pockets and are thus carried laterally to the loading station 4. The width of the individual pockets of the bags will be preadjusted for a given batch of articles se that the pockets will be capable of accepting the largest articles within the tolerance range of that particular batch, but there will at no time be any considerable discrepancy between the pocket width and the article width.

The articles may, for example, be of cylindrical form such as "continental sausage" or cheeses of similar shape.

Attempting to feed such articles in a longitudinal direction along a conveyor gives problems due to the tendency of the articles to roll, but by having the various pockets of the conveyor dimensioned to match the diameter of the cross-section of the article and open at at least the side of the conveyor nearer to the bag-separating station 3, the article conveyor is capable of handling such difficult articles with relative ease.

The bag-separating mechanism illustrated in Figs. 1 and 2 comprises a series of bag holding members as follows: A first bag clamping means comprises a hold-down member 6 vertically reciprocable along the direction of arrow 7 towards and away from the guide 2 so that when the bag hold-down member 6 is in its lowest position it clamps the chain 8 of laterally facing, sidesealed perforated bags 8a, 8 b, 8c, 8d, 8e (Fig. 2) in order to prevent further movement of the bag chain upstream of the hold-down member 6, i.e. between the supply roll 1 and - the hold-down member 6. The first bag clamping means always operates at a fixed position along the guide 2.

A second bag clamping means 10 comprises a vertically movable upper hold-down member 11 movable vertically along the direction of arrow 1 2 towards and away from a vertically fixed counterpressure member 1 3 so that the second bag clamping means 10 is capable of selectively clamping and releasing the bag chain, as does the first bag clamping means. However, in contrast to the first mentioned bag clamping means, the second bag clamping means 10 is movable horizontally along the direction of the bag chain (see arrows 14 in Fig. 2).

A third bag clamping means 15, again movable horizontally (along the direction of arrows 1 4a in Fig. 2), comprises an upper hold-down member 1 6 movable vertically along the direction of arrow 1 7 towards and away from a vertically fixed counterpressure member 1 8. The entire third clamping means 1 5 is, as mentioned above, movable horizontally and co-operates with the upstream second bag clamping means 10 to sever one bag of the chain from the next successive bag on the chain and advances the severed bag to the bag loading station 4.

A pneumatically operated fourth bag clamping means 1 9 (see Fig. 4) is positioned near one side of the apparatus, clear of the path of movement of the third bag clamping means 1 5 and remains at a fixed position but is free to open and close to selectively release and clamp the appropriate bag 8a, .... . of the chain 8.

A fifth bag clamping means, also illustrated in detail in Figs. 3a, 3b and 3c, comprises a bag pincer mechanism having a hold-down member 20 movable towards and away from a fixed counterpressure member 21. This fifth bag clamping means again operates at a fixed location and just clear of the path of movement of the third bag clamping means 1 5.

As shown by the schematically-illustrated mechanical connections 22 and 23 in Fig. 1, the horizontally movable second bag clamping means 10 is carried by a slide 24 on a fixed guide bar 25, and the horizontally movable third bag clamping means 1 5 is carried by a similar slide 26 on the bar 25. One end of the slide bar 25 is received in a support wall 27 near the bag loading station, and the other end is received in the opposite wall 28 near the support for the supply roll 1 of lateratly facing, side-sealed perforated bag material.

The second bag clamping means 10 is driven by a ram 29 and the third bag clamping means 1 5 is driven by a ram 30, the timing of the operation of the two rams 29 and 30 being evident from the description below of the functioning of the apparatus.

The side elevational view of Fig. 1 shows a photoelectric bag detector means 31 which senses the presence of the leading edge of the first bag 8a at a line 32.

The geometry of the device is such that at the start of bag separating movement the third bag clamping means 1 5 should always be in the position illustrated in Fig. 2 where its centre line is coincident with the line 15a.

In order to ensure that the separating mechanism is adjustable for different bag widths, the position of the photoelectric bag sensor 31 is adjustable longitudinally of the machine by means of a linkage schematically illustrated by a strut 33 connecting the mounting for the sensor 31 to one end of a lever 34 whose other end is articulated to a nut 35 on a lead screw 36 adjustable by means of a hand wheel 37. The lever 34 has a fulcrum 38 (Fig. 2). Providing a support surface, on which all of the bag-separating actions takes place, is a conveyor belt 39 which advances the loaded bag from the bag loading station 4 rightwardly towards a bag evacuation and sealing station 47. The conveyor belt 39 has upstanding pins 40 on which the bag is impaled by means of a bag pressing device 48, described below, to ensure positive advance from the loading station.

The above-mentioned lead screw 36 is also effective to adjust the position of the path of travel of the second bag clamping means 10 by virtue of a mechanical interconnection 41 between the nut 35 and the cylinder of the ram 29. As the lead screw 36 is rotated to move the nut rightwardly as viewed in Fig. 1, the cylinder 29 is itself carried rightwardly and consequently the two extremes of movement of the second bag clamping means 10 are themselves moved rightwardly, in order to ensure that when a chain whose bags are of a width different from the previously used chain 8 is to be loaded for use in the apparatus, the path of movement of the second bag clamping means 10 is always correctly registered with the lines of predetermined weakness comprising perforation lines between the bags, so that the second bag clamping means 10 will always engage a bag without straddling the line of separation between one bag and the next.

The convenience of the apparatus as illustrated is that a single lead screw handle 37 will allow simultaneous adjustment of both the position of the cylinder of the ram 29 and the position of the photoelectric bag sensor 31, and the lead screw nut 35 can be provided with a suitable calibration scale which can be related to the width of bag to be fed.

The adjustment of the position of the bag sensor 31 is such that the distance between the line 1 5a (Fig. 2) and the position of the sensor 31 is always exactly half of the bag width being fed. This will ensure that when the leading edge of the bag chain arrives at the sensor 31 the centre line of the leading bag 8a will be coincident with the line 1 spa.

At the bag loading station there is a pair of bag spreading plates 42 which enter the mouth of the loaded bag, by movement parallel to the direction of the movement of the article-pushing member 5, and are then moved away from one another in order to spread the mouth of the bag flat. Once the bag is spread in this way, the bag pressing device 48 descends to press the flattened bag mouth onto the pins 40 in order to ensure positive holding of the loaded bag on the conveyor belt 39.

The third bag clamping means 1 5 is connected to a piston rod of its ram 30 by a vertically extending pivot axis 42 which allows some swinging of the entire bag clamping means 1 5 along the direction of the arcuate arrow 43. This swinging movement is resiliently resisted by a spring which biases the hold-down member 1 6 and its counterpressure member 1 8 towards the Fig. 2 position when the third bag clamping means 1 5 opens.

At the end of the bag hold-down member 1 6 opposite to that where the pivot axis 42 is located, there is a suction pad 44 which can be activated in order to attract the upper wall of the clamped bag 8a as the bag hold-down member 1 6 rises.

This serves to initiate bag opening movement which is then followed up by means of an inflation air jet.

The operation of the entire bag-separating mechanism will now be described with reference to the drawings.

Firstly, a supply roll 1 having a chain 8 of the appropriate side-sealed bags is placed with its shaft 45 in the schematically-illustrated bearings 46 and the leading edge of the chain 8 of bags advanced over the guide 2 until the leading bag 8a is positioned directly beneath the bag hold-down member 11 of the second bag clamping means 10. The operating hand wheel 37 of the lead screw 36 is, if necessary, rotated in order to bring the lead screw nut 35 into the appropriate position for the width of the bags 8a, 8b, .... . being fed, thereby simultaneously adjusting the position of the bag sensor 31 and the ram 29 of the second bag clamping means 1 0.

The apparatus is then energised by switching on a compressed air supply which will cause the bag hold-down member 6 of the first bag clamping means to close onto the guide 2 to hold the bag 8b (in the position illustrated by bag 8c in Fig. 2). Simultaneously, the switching on of the compressed air supply will cause the bag hold-down member 11 of the second bag clamping means 10 to descend to clamp the lead bag 8a (in the position shown by the bag 8b in Fig. 2) against the corresponding counterpressure member 13.

The operation of the machine is then initiated and the first step will be for the bag hold-down member 6 to rise, releasing the run of bags between the second bag clamping means 10 and the supply roll 1. At this stage the second bag clamping means 10 advances rightwardly along the direction of the arrow 14 (Fig. 2) to draw the first two bags 8a and 8b into their positions actually illustrated in Figs. 2 and 4. Movement of the second bag clamping means 10 is stopped once the leading edge of the lead bag 8a is sensed by the bag sensor 31. During this movement, the third bag clamping means 1 5 will be at the bag loading station 4 and will consequently leave room for the second bag clamping means 10 to arrive in line with the line 1 5a of Fig. 2.

When the advancing movement of the second bag clamping means 10 ceases, the fourth bag clamping means 1 9 is operated to clamp a projecting lower lip of the bag mouth.

This allows the second bag clamping means 10 to open and to return to its position shown in Figs. 1 and 2 where the second bag clamping means 10 is about to clamp the second bag 8b.

Once the second bag clamping means 10 has retreated to vacate the position on the line 1 5a of Fig. 2, the third bag clamping means 1 5 can retract from its loading station position to arrive at the position shown in Fig. 2 where it is about to close onto the lead bag 8a. It then closes to hold the bag 8a while the second bag clamping means 10 is already holding the next bag 8b. In this position the line of perforations between lead bag 8a and the next successive bag 8b is betwen the second and third bag clamping means 10 and 15, respectively, with the second bag clamping means on the upstream side of the line and the third bag clamping means 1 5 on the downstream side of the line.These two bag clamping means are then ready to carry out the bag-separating action to separate the first bag 8a from the rest of the chain 8 comprising the second and subsequent bags 8b, 8c, 8d ....

The fourth bag clamping means 1 9 releases the lower lip of the bag mouth to allow the now closed second and third bag clamping means 10 and 15, respectively, to carry out the bag-separating function in that the pivot axis 42 of the third bag clamping means 1 5 moves away from the second bag clamping means 10 and, by virtue of the ability of the hold-down member 1 6 and the counterpressure member 18 of the third bag clamping means 1 5 to swing about the axis 42, the tension imposed on the rear end of the perforation line between the bags 8a and 8b (i.e.

the end near the closed ends of those bags) will be higher than the bag-separating tension imposed anywhere else across the chain 8 and consequently progressive rupture of the separation line between the two bags will be provoked.

Once the forward movement of the third bag clamping means 1 5 has progressed so far that the perforation line between the bags 8a and 8b is broken along its full length, the biasing spring (not shown) of the third bag clamping means 1 5 causes the bag holddown member 1 6 and its counterpressure member 1 8 to swing to a position in which they once again extend exactly transversely across the direction of movement of the bag chain. Advancing movement of the third bag clamping means 1 5 continues to advance the leading bag 8a to the bag loading station and in so doing the lead bag 8a has its free lip entering a slot between the upper and lower bag members 20 and 21 of the fifth bag clamping means.When the third bag clamping means 1 5 arrives at its position exactly centrally of the bag loading station 4 the fifth bag clamping means 20 is operated to clamp the lower lip of the bag. This "lip" is formed only on the lower wall of the bag in that the bag chain is formed such that it comprises a folded web to define bags such that each bag has a lower wall joined to an upper wall by the fold line extending along the closed end of the bag, and the lower wall is the longer one, having this lip projecting laterally to be engaged by the bag pincer 20, 21. Thus it is possible for the lower wall to be clamped (by the action of the fifth bag clamping means on the lip of the bag 8a) while leaving the upper wall of the bag free to be raised for opening and loading.

Raising of the upper wall of the bag 8a is achieved by actuation of the above mentioned suction pad 44 on the bag hold-down member 1 6 of the third bag clamping means 1 5 so that as the bag hold-down member 1 6 rises along the direction opposite to that shown by the arrow 1 7 in Fig. 1, the top wall of the bag is lifted and an inflation air jet can be actuated to complete the bag opening operation.

At this stage, the leading edge of the bag 8a is held by the fifth bag clamping means 20, 21 (as shown in Fig. 3a) so the third bag clamping means 1 5 is free to retract to the Fig. 2 position to start the next separating action in that while the first bag 8a was being advanced to the loading station the next bag 8b was being carried by the second bag clamping means 10 from the Fig. 2 position to the position shown for the bag 8a in Fig. 2.

Thus, while the bag loading operation takes place at the bag loading station 4, the separating of the next two bags 8b and 8c at their common perforation line can be carried out by the upstream and downstream second and third bag clamping means 10 and 15, respectively. This amounts then to the next cycle of operation of the machine.

Once the article-pushing member 5 has inserted an article fully into the now pneumatically inflated bag 8a at the loading station 4, as shown in Fig. 3b, the two bag spreading plates 42 enter the bag mouth and then move apart to flatten the bag when the inflation air jet is de-activated.

Finally, as shown in Fig. 3c, the bag pressing device 48 descends onto the pins 40 to impale both lips of the bag 8a onto the pins 40 so that when the conveyor belt is indexed the bag will automatically be carried forward into the vacuum chamber 47.

As shown in Fig. 4, the counterpressure member 1 3 of the second bag clamping means 10 holds the bag (for example 8b) above the pins 40 so the various bags held simultaneously by the second and third bag holding means 10 and 15, respectively, can be pulled apart from one another to separate the bags without those bags being torn by the pins 40.

It will be understood that the entire sequence of events described above will then continue repetitively either until the particular batch of articles has been loaded and evacuated or until the bag supply needs to be changed.

Claims (21)

1. Apparatus for separating and loading bags from a chain of side-sealed laterally extending packaging bags, comprising downstream bag-holding means adapted to engage a first bag of the chain to one side of a line of predetermined weakness separating two bags of the chain when said first bag is in a first position; upstream bag-holding means adapted to engage a second, adjacent bag of said chain at the other side of said line of predtermined weakness when said second bag is in a second position; means for separating the downstream and upstream bag-holding means by relative movement in a direction so as to separate the said first bag from the said second bag of the chain by applying a separating tension across the said line of predetermined weakness such that the tension at one end of said line is greater than at the other; means operative to control said upstream bagholding means to release said second bag after completion of separation of the first bag therefrom and to drive said upstream bagholding means along the bag chain to clamp a third bag of said chain adjacent the line of predetermined weakness separating that third bag from the immediately preceding bag of the chain; means for advancing the said first bag, after separation, to a bag-loading station; and means for opening said first bag at said bag-loading station.

2. Apparatus according to claim 1, wherein said downstream and upstream bagholding means each comprise a respective clamping member adapted to engage one side of said bag chain, and a respective counterpressure clamping member adapted to engage the other side of said bag chain, with means for effecting approaching and separating movement of said clamping member and counterpressure member of the respective said downstream and upstream bag-holding means to achieve clamping and releasing of the associated bag of the chain.

3. Apparatus according to claim 2, wherein said downstream bag-holding means has its clamping member and its counterpres sure member pivotally attached to a driven frame which is adapted to move towards and away from said upstream bag-holding means, the axis of pivoting of said clamping member and counterpressure member of said downstream bag-holding means being disposed to one side of the path of said bag chain and outside the anticipated confines of said bag chain, whereby said pivoting movement of the clamping member and counterpressure member of said downstream bag-holding means relative to said driven frame achieves greater tension on that end of the predetermined line of weakness between said first and second bags which is adjacent said pivot axis, than on the opposite end of said predetermined line of weakness, in order to provoke rupturing of the bags at said predetermined line of weakness.

4. Apparatus according to claim 2 or 3, wherein said means for opening said first bag at said bag-loading station comprises a suction pad carried by the said bag clamping member of said downstream bag-holding means.

5. Apparatus according to claim 2, 3 or 4, wherein said counterpressure members of said downstream and upstream bag-holding means are each at a fixed level, and are movable along the direction of the bag chain in order to achieve separation of the first bag from the second bag, and wherein said means for effecting approaching and separating movement of said clamping member and counterpressure member of the respective bag-holding means comprise rams operative to raise and lower said clamping members with respect to said counterpressure members of the respective one of said downstream and upstream bagholding means.

6. Apparatus according to any one of the preceding claims, and further including a belt conveyor to transport said first bag to and from said bag-loading station after separation by said downstream and upstream bag-holding means; and wherein said separating movement of said downstream and upstream bagholding means is in a direction parallel to the direction of movement of said belt conveyor to and from said bag loading station.

7. Apparatus according to claim 6, wherein said relative separating movement between said downstream and upstream bagholding means comprise forward movement of said downstream bag-holding means along the direction of conveyor advance, while said upstream bag-holding means remains stationary.

8. Apparatus according to claim 6 or claim 7, wherein said belt conveyor includes a plurality of upstanding pins positioned to pierce a side wall of said first bag to facilitate transport of said first bag to said bag-loading station and onwardly from said bag-loading station.

9. Apparatus according to any one of claims 6 to 8, and further including a vacuum chamber cooperating with said conveyor belt to evacuate said first bag, after loading, in order to allow the bag to be closed under vacuum

1 0. Apparatus according to claim 9, wherein said vacuum chamber includes means for closing and sealing said first bag in said vacuum chamber.

11. Apparatus according to any one of claims 6 to 10, wherein said means for achieving separating movement of said downstream bag-holding means and said upstream bag-holding means to achieve separation of the first and second bags comprise a first ram operable to drive said downstream bag-holding means.

1 2. Apparatus according to claim 11, and further including a second ram operative to drive said upstream bag-holding means rearwardly along the bag chain to clamp said third bag and then forwardly to advance said third bag to said second position for separation of said preceding bag therefrom.

1 3. Apparatus according to claim 12, and including means for adjusting the stroke of said second ram to accommodate adjustment of said bag separating apparatus for chains of bags having different bag widths.

14. Apparatus according to any one of the preceding claims, and including photosensitive bag registration means to stop forward movement of said upstream bag holding means when the leading edge of said third bag arrives at said second position.

1 5. Apparatus according to claim 14, when appendant to claim 13, wherein said means for adjusting the stroke of said second ram further includes means for adjusting the position of said photosensitive bag registration means to accommodate bags of different widths in said second position.

16. A method of separating and loading side-sealed bags of a continuous chain of laterally extending packaging bags joined by lines of predetermined weakness between the side seals of adjacent ones of said bags, comprising: advancing said chain of bags to a bag-separating location; holding a first one of said bags adjacent its side seal and to one side of said line of predetermined weakness between said first bag and a next successive, second bag; holding said next successive sec- .

ond bag adjacent its side seal at the other side of said line of predetermined weakness; pulling said first bag forwardly along a direction away from said next successive second bag while imposing greater tension on one end of said line of predetermined weakness than on the other end of said line of predetermined weakness; continuing said separating movement of said first bag away from said second bag until completion of rupture along the full length of said line of predetermined weakness to achieve total separation of said first bag from said second bag; carrying said first bag forwardly to a bag-loading station; at or before said bag loading station, opening said first bag for loading of an article thereinto; simultaneously with said advance of the first bag to said bag-loading station gripping a third bag adjacent its side seal to one side of said line of predetermined weakness between that third bag and the next preceding bag; and finally drawing said gripped third bag forwardly to bring the said line of predetermined weakness between the third bag and the next preceding bag into registration with the previous position of the line of predetermined weakness between said first and second bags.

1 7. A method according to claim 16, wherein said next preceding bag is said second bag.

1 8. A method according to claim 1 6 or claim 17, wherein said opening of the first bag at or before said bag-loading station is achieved by lifting one side wall of said bag away from the other side wall thereof as the gripping action on said first bag is released.

1 9. A method according to claim 16, 1 7 or 18, wherein said line of predetermined weakness between adjacent ones of said bags of the chain comprises a continuous perforation line extending across the bag chain at each interval between successive bags.

20. Apparatus for separating and loading bags from a continuous chain of laterally extending side-sealed bags joined to one another along predetermined lines of weakness between the side seals of adjacent bags of said chain, such apparatus being constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

21. A method of separating and loading bags from a continuous chain of side-sealed laterally extending bags joined together along their side seals by lines of predetermined weakness of the bag chain, such method being substantially as hereinbefore described with reference to the accompanying drawings.