US3481102A

US3481102A - Bag forming methods and apparatus

Info

Publication number: US3481102A
Application number: US603020A
Authority: US
Inventors: Austin Dolman
Original assignee: Hill & Dolman Eng Ltd
Current assignee: Hill & Dolman Eng Ltd
Priority date: 1965-12-18
Filing date: 1966-12-19
Publication date: 1969-12-02
Anticipated expiration: 1986-12-02
Also published as: GB1173744A; DE1511649A1; FR1505201A

Description

Dec. 2, 1969 A. DOLMAN 3,431,102

' BAG FORMING METHODS AND APPARATUS Filed Dec. 19, 1966 3 Sheets-Sheet 1 Dec. 2, 1969 A. DOLMAN 3,431,102

' BAG FORMING METHODS AND APPARATUS Filed Dec. 19, 1966 5 Sheets-Sheet 2 v 3 "k' 5v I E i vemlup MQM M, V biz mamas.

A. DOLMAN BAG ponmme mmnons AND APPARATUS Dec. 2,1969

3 Sheets-Sheet 5 Filed Dec. 19, 1966 lwevul-oeJ Mawg United States Patent 3,481,102 BAG FORMING METHODS AND APPARATUS Austin Dolman, Norwich, Norfolk, England, assignor to Hill & Dolman (Engineers) Limited, Norwich, Norfolk, England, a British company Filed Dec. 19, 1966, Ser. No. 603,020 Claims priority, application Great Britain, Dec. 18, 1965, 53,759/ 65 Int. Cl. B65b 43/00 US. CI. 53-29 21 Claims ABSTRACT OF THE DISCLOSURE An apparatus for forming a succession of filled bags from a continuous length of flexible tubing fed through the apparatus, and comprising a device for forming spaced transverse slits in the tubing wall, device for sealing the tubing across its width at locations between the slits so as to form a succession of connected bag portions between each slit and a sealed part, a device for dispensing goods through the slits into each bag portion, a device for sealing the connected filled bag portions, and a device for severing each filled bag from the length of tubing upon its completion, each portion of the tubing which is to become a filled bag being fed past all the devices in succession.

The invention relates to bag forming methods and apparatus and particularly to methods and apparatus for forming filled bags from a continuous length of flexible tubing.

According to the invention a method of forming filled bags from a continuous length of flexible tubing com prises the steps of forming a succession of spaced transverse slits in a part of the wall of the tubing, sealing the tubing across its width at a succession of locations alternating with the slits so as to provide a bag portion to one side of each slit and between that slit and a sealed part of the tubing, introducing the required contents through each slit into each bag portion, and sealing the tubing across its width on that side of each slit nearer the sealed part whereby the contents are sealed within each said bag portion. Each filled bag in succession may be severed from the length of tubing.

Preferably the tubing is fed intermittently past means for eflecting the operations referred to, each operation being performed when the tubing is temporarily stationary.

The tubing may be an extruded, seamless tubing or may be formed by joining the opposed longitudinal edges of a strip or strips of flexible material.

Apparatus for carrying out any of the methods referred to above may comprise means for feeding the flexible tubing through the apparatus, means for forming a succession of spaced transverse slits in a part of the wall of the tubing, means for sealing the tubing across its width at a succession of locations alternating with the slits so as to provide a bag portion to one side of each slit and between that slit and a sealed part of the tubing, means for introducing the required contents through each slit into each bag portion and means for sealing the tubing across its width on that side of each slit nearer the sealed part, whereby the contents are sealed Within each said bag portion.

There may be provided means for opening out the tubing at a location adjacent said means for forming slits in the wall of the tubing, whereby the slit forming means severs only part of the wall of the opened out tubing. For example, the means for opening out the tubing may comprise a member disposed within the tubing and shaped to support a portion of the wall of the tubing in a position 3,481,102 Patented Dec. 2, 1 969 "ice out of contact with any other part of the wall, said slit forming means being adapted to form a slit in said portion of the wall of the tubing.

Preferably said member is floating within the tubing and is restrained against movement with the tubing by fixed bearing elements outside the tubing.

In the case where the tubing is moved upwardly the weight of the floating member may be arranged to maintain it in position within the tubing.

In a further form of the method according to the invention, at least a portion of the flexible tubing is flattened and each said slit is formed by severing both opposed walls of the flattened tubing along a line extending from one longitudinal edge of the flattened tubing to a point intermediate its longitudinal edges, and then re-flattening the tubing in a plane substantially at right angles to the plane containing those longitudinal edges whereby at least the major part of the slit lies in one wall of the re-flattened tubing.

The flexible tubing may be initially in a flattened state and at least a portion of the flattened tubing is first flattened in a plane substantially at right angles to its initial plane, a slit then being formed by severing both opposed walls of the flattened portion along a line extending from one longitudinal edge of the flattened portion to a point intermediate of its longitudinal edges, and the portion is then re-flattened in its original plane whereby at least the major part of the slit lies in one wall of the re-flattened tubing.

Apparatus for carrying out either of the last mentioned methods may comprise means for severing both walls of flattened tubing along a line extending from one longitudinal edge of the flattened tubing to a point intermediate its longitudinal edges, and means for re-flattening the tubing in a plane substantially at right angles to the plane containing those longitudinal edges whereby at least the major part of the slit lies in one wall of the re-flattened tubing.

The apparatus may comprise means for flattening at least a portion of already flattened tubing in a plane substantially at right angles to its initial plane, means for severing both walls of the flattened portion along a line extending from one longitudinal edge of the flattened portion to a point intermediate its longitudinal edges, and means for re-flattening said tube portion in its original plane whereby at least the major part of the slit formed by the severing means lies in one wall of the re-flattened tubing.

The means for flattening a portion of the already flattened tubing in a plane substantially at right angles to its original plane may comprise a member disposed within the tubing and shaped to expand the tubing in a direction substantially at right angles to its original plane as it passes over the member thereby flattening the tubing in a plane at right angles to said original plane.

The means for re-flattening said tube portion in its original plane may also comprise a member disposed within the tubing and shaped to expand the tubing in a direction substantially parallel to its original plane.

Each of said members is preferably floating within the tubing and is restrained against movement with the tubing by fixed bearing elements outside the tubing. In the case where the tubing is moved upwardly over the floating members the weight of the members may be arranged to maintain them in position within the tubing.

Said two members may be connected together to form a unitary floating structure.

In any of the above arrangements the means for forming said slits in the tubing comprise a movable knife or a hot wire cutter.

In any of the above arrangements there may be provided means for opening out each said bag portion whereby said contents may readily be introduced into each bag portion, for example there may be provided blower means for directing a blast of air through each said slit to expand each bag portion.

Preferably means are provided for stretching the tubing across its width adjacent each said slit before the tubing is sealed across its width on that side of each slit nearer the first said sealed part.

The following is a more detailed description of various embodiments of the invention reference being made to the accompanying drawings in which:

FIGURE 1 is a diagrammatic view of an apparatus for forming filled bags from a continuous length of flexible tubing;

FIGURE 2 is a perspective view of the means employed in the apparatus of FIGURE 1 for forming a succession of spaced transverse slits in the tubing;

FIGURE 3 is a perspective view of certain parts of the apparatus of FIGURE 1 showing the means by which the bags are filled, sealed and severed;

FIGURE 4 is a perspective view of an alternative means to that shown in FIGURE 2 for forming a succession of spaced transverse slits in the tubing; and

FIGURE 5 shows a further alternative means for forming a succession of spaced transverse slits in the tubing and for forming the tubing from a strip of material.

Referring to FIGURE 1: there is provided a holder for a supply reel 11 of flattened flexible tubing 12.

The tubing 12 may be formed from any thermoplastic material, such as polythene, and may comprise flattened seamless extruded tubing, or tubing folded from a single flat strip of material and joined along one longitudinal edge, or tubing formed from two flat strips of material joined together at both longitudinal edges thereof.

After leaving the reel 11 the flattened tubing passes around idler rollers indicated at 13 and 14 and then through a slitting device, to be described in detail later, indicated at 15. As will be described the slitting device 15 forms a series of transverse slits in a part of the wall of the tubing as the tubing is moved intermittently through the apparatus. In the arrangement shown each slit is at right angles to the length of the ubing and ex tends completely across one face of the flattened tubing from one longitudinal side edge to the other,

Upon leaving the slitting device 15 the tubing passes between a pair of

feed rollers

16, 17 which are drivably connected by engaging spur gears 18 (see FIGURE 3). The shaft 19 carrying the feed roller 16 is driven through a one-revolution clutch 20 from an electric motor 21. The diameter of the feed roller 16 is such that during one revolution of the roller the tubing is fed through the apparatus for a distance corresponding to the length of the bags to be formed from the tubing. The' one-revolution clutch is tripped in a manner to be described below.

After leaving the

feed rollers

16, 17 the tubing 12 passes over a further idler roller 22 and moves vertically downwards as it leaves this idler roller.

Disposed adjacent the idler roller 22 is an air pipe 23 which is in communication with a blower indicated diagrammatically at 23a in FIGURE 1. When the tubing is at rest one of the transverse slits previously formed by the slitting device 15 is disposed adjacent the roller 18 and the tubing is sealed across its width (by a sealing bar 34 to be described below) at a distance below the slit slightly greater than the length of the bags to be formed. The air pipe 23 is so disposed as to direct a blast of air through the slit which is adjacent the roller 22 so as to expand the bag portion below that slit. A funnel 24 has its lower end disposed adjacent the end of the air pipe 23 and is so mounted on a fixed part of the apparatus as to be movable in an up and down direction. The shaft 19 carrying the roller 16 has secured to one end thereof a cam wheel 25 which is engaged by a cam follower 26 on the end of an arm 27. The arm 27 is secured to one end of a shaft 28 which is rotatable in a fixed bearing 29. The opposite end of the shaft 28 has mounted thereon a further arm 30 having a part 31 which is engageable with a part mounted on the funnel 24. Thus the cam 25 normally keeps the funnel 24 in a raised position but at the end of each revolution of the roller 16, as the tubing comes to rest, the follower 26 comes to a fall in the cam 25 and lowers the lower end of the funnel 24 into the slit across the tubing which has been blown open by the air blast from the pipe 23. A dash-pot 32 is coupled by means of a linkage 33 to the shaft 28 to dampen the downward movement of the funnel 24 so that the slit has time to be opened by the air blast before the funnel is lowered into it. When the lower end of the funnel has entered the slit, a predetermined quantity of the goods to be bagged, for example nuts, is delivered through the funnel into the bag portion. The goods may be delivered by hand into the funnel or by a known form of automatic dispensing device arranged to operate in synchronism with the rest of the apparatus.

Spaced below the roller 22 are two

inpulse sealing bars

34 and 35. The sealing bars extend across the width of the tubing and are movable into and out of engagement with the tubing in a manner to be described. As best seen in FIGURE 1 the upper sealing bar 34 is disposed at such a distance below the idler roller 22 that when one transverse slit in the tubing is level with the idler roller 22, the preceding transverse slit is disposed slightly below the upper sealing bar 34. When the tubing stops in this position, as shown in FIGURE 1, the two sealing bars are moved into engagement with the tubing to seal it across its width and, as described above, the upper sealing bar 34 forms a bag portion below the slit which is level with the idler roller 22.

The two

sealing bars

34 and 35 are mounted respectively on spaced

parallel cross-bars

36, 37 at the upper end of a swinging frame 38 the lower end of which has secured thereto a shaft 39 which is rotatable in fixed bearings 40. A lever arm 41 is secured to one end of the shaft 39 and its free end is connected to the end of the piston rod 42 of a vacuum cylinder 43. Thus when the vacuum cylinder 43 is operated to retract the piston rod 42 the frame 38 is swung clockwise (as seen in FIGURE 1) to bring the sealing bars 34 and 35 into engagement with the tubing. As it swings clockwise a part of the frame 38 is arranged to operate a micro-switch (not shown) to operate the sealing bars 34, 35, in known manner, so that a high current impulse passes through them and seals the tubing across its width at the two locations where it is engaged by the sealing bars. The vacuum cylinder may be operated by an operator closing a manual switch or may be arranged to be automatically operated periodically.

Between the sealing bars 34 and 35 there is disposed a spreading device indicated generally at 44 in FIGURE 1. The spreading device comprises a rectangular section support bar 45 extending between the upper ends of two arms 46 and 47 which are pivotally mounted at their lower ends so as to swing about a horizontal axis parallel to the plane of the flat tubing. A fixed spreader arm 48 projects from the bar 45 towards the tubing and has at its end a downwardly projecting finger 49. Movable spreader arms 50 having similar downwardly extending fingers 51 are carried by sleeves 52 which are slidable on the bar 45. The sleeves 52 are connected by a helical tension spring 53 which urges the fingers 51 on the spreader arm 50 together and into contact with the finger 49 on the fixed spreader arm 48. Mounted on the sleeve 52 are roller cam followers 54 which are engaged by cam tracks 55 mounted on the opposite ends of the aforementioned bar 36 on the swinging frame 38 which carries the sealing bars. Two helical tension springs 56, 57 are connected between the arms 46 and 47 respectively and fixed parts of the apparatus and urge the fingers 49 and 51 towards the tubing. There is mounted on the swinging frame 38 an arm 58 which extends past the arm 46 on the spreading device and has a hooked end 59 whichis engageable with the arm 46.

In operation, when the tubing is at rest, a bag portion which has just been filled by goods fed through the funnel 24 has moved down until the open slit at its upper end is disposed between the upper and lower sealing bars 34 and 35, and the fingers 49 and 51 are at this time adjacent one another to form a single downward projection. The vacuum cylinder 43 is then operated to swing the frame 38 towards the tubing. As the frame 38 swings the heater bars 34 and 35 towards the tubing the spreading device also swings towards the tubing under the action of the

springs

56 and 57. The spreading device continues to swing until the single projection constituted by the fingers 49 and 51 is moved into the open slit at the top of the bag portion (which slit is open due to the weight of the contents within the bag portion) and presses the tubing against a fixed support behind it. At this point the swinging movement of the spreading device is arrested but the frame 38 continues to swing towards the tubing. As it does so the cam tracks 55 urge the sleeves 52 outwardly away from one another against the action of the spring 53 so that the fingers 51 move apart and stretch out sideways the slit at the top of the bag portion, thus flattening the top of the bag portion and freeing it from wrinkles. As the fingers 51 reach the outward limit of their movement and the upper part of the bag portion is stretched, the sealing bars 34 and 35 come into engagement with the tubing above and below the spreading device respectively, and, as described above, the lower sealing bar 35 seals the top of the previously filled bag portion and the upper sealing bar 34 seals the bottom of the next bag portion which is about to be filled. This bag portion is then filled with the required contents passing down the funnel 24 which has been inserted into the open top of the bag portion, as described above. When this bag portion has been filled the vacuum cylinder 43 is operated (manually or automatically) to swing the frame 38 away from the tubing. As the sealing bars 34 and 35 on the frame 38 are swung away from the tubing a part (not shown) on the frame 38 trips the one-revolution clutch referred to earlier to rotate the feed roll 16 through one revolution to feed the flattened tubing a predetermined distance through the apparatus. The two sealed parts of the tubing which have just been scaled by the bars 34 and are thus moved downwardly until they come opposite a severing device indicated generally at in FIGURE 1.

As best seen in FIGURE 3 the severing device 60 consists of two spaced stationary knife blades 62 and a pivoted double-edged knife blade 63. The pivoted knife blade 63 is pivoted at one end at 64 and is connected by a link 65 to a cross bar 66 on the swinging frame 38. Thus each time the tubing is at rest and the swinging frame 38 is swung towards the tubing the blade 63 is swung between the fixed blades 62 and severs a narrow strip, containing the original tranverse slit, from the tubing between the sealed part of the top of one bag portion and the sealed part of the bottom of the following bag portion. The bag portion below the severing device 60 then falls on to a delivery chute (not shown) leading to a collection point.

To ensure an effective severing action between the pivoted blade 63 and the fixed blades 62, the two blades 62 are pivoted at 67 at one end thereof and at the opposite end are held together by a tension spring 68, so that the spacing between the fixed blades 62 at the end thereof near the tension spring 68 is slightly less than the thickness of the pivoting blade 63. Thus as the pivoting blade 63 swings betwen the fixed blades 62 it forces them apart and thus is maintained in close shearing engagement with both of them.

It will be appreciated that each time the tubing is stationary, the slitting device 15, the

filling mechanism

23, 24, the sealer bars 34, 35, the sperader device 44,

and the severing device 60 all operate on different parts of the tubing to perform operations in the forming of a filled bag.

FIGURE 2 shows in further detail the construction of the slitting device 15. There is disposed within the tubing a floating structure 69 which comprises a lower member 70 and an upper member 71 connected by a bar 72. The lower member 70 is of a double wedge shape and is prevented from falling downwardly within the tubing 12 by hearing plates 73 disposed outside the tubing. The bearing plates 73 are welded to collars 74 which are adjustably mounted on fixed support shafts 75 so that the angle and position of each plate 73 may be adjusted. The double wedge member 70 is rebate shaped such that as the flattened tubing 12 passes upwardly over it it is expanded in a direction at right angles to its initial plane so as to be flattened in a plane at right angles to that initial plane. The upper member 71 which is also of double wedge shape operates in the reverse manner to re-flatten the tubing into its initial plane. Bearing members 76 are disposed outside the tubing at the location of the upper member 71 to locate that member. Thus the portion of tubing between the lower and upper members 70 and 71 is temporarily flattened in a plane substantially at right angles to its initial plane.

Adjacent this temporarily flattened portion of the tubing is disposed a fixed knife blade 77 with which cooperates a pivoting knife blade 78. The length of the pivoting blade 78 is such that as it closes on the fixed blade 77 it severs the opposed walls of the temporarily flattened portion of the tubing along a line extending from one longitudinal edge of the portion to a point approximately midway between its longitudinal edges. Thus when the tubing is re-flattened in its original plane again by the upper member 71 the slit formed by the knife blades 77 and 78 (as shown by the slit 79 in the upper part of FIGURE 2) extends across one face of the reflattened tubing from one longitudinal edge to the other.

A pressure arm 80 is pivotally mounted at 81 on the fixed blade 77 and is normally disposed in engagement with the intermediate flattened portion of the tubing, so as to hold the intermediate portion of the tubing flat against the fixed blade 77 as the moving blade 78 operates upon it. The arm 80 is pivotally mounted so that it may be swung aside when a new length of tubing is initially being fed through the apparatus.

The moving blade 78 is mounted on the upper end of an upright shaft 82 which is rotatable in a fixed bearing 83. Secured to the lower end of the shaft 82 is a lever arm 84 which, as seen in FIGURE 3, is connected by a connecting rod 85 to a part of the swinging frame 38. Thus each time the tubing is stationary and the frame 38 is swung towards the tubing, the shaft 82 is pivoted by the

linkage

84, 85 so as to swing the blade 78 into engagement with the fixed blade 77.

FIGURE 4 shows an alternative arrangement to that shown in FIGURE 2 for forming the transverse slits in the tubing. In the arrangement of FIGURE 4 there is provided a single floating member 86 within the tubing. The member is bent from sheet metal and has a lower V shaped part 87 which is disposed between angled bearing plates 88 disposed outside the tubing and secured to collars 89 mounted on fixed support shafts 90. The bearing plates 88 prevent the member 86 falling downwardly in the tubing under its own weight. It will be seen that the member 86 opens out the tubing so that a portion of one face of the tubing extends unsupported between the lower V-shaped part 87 of the member and its upper edge 91. A hot wire cutter 92 is disposed adjacent the member 86 and each time the tubing comes temporarily to rest the wire of the hot wire cutter is automatically moved into engagement with the unsupported portion of the tubing so as to form the transverse slit 79 across one face of the tubing. The hot wire cutter 92 is connected by a linkage to the swinging 7 frame 38 in a similar manner to the pivoted blade 78 in the arrangement of FIGURE 2.

FIGURE 5 shows a further alternative device for forming the transverse slits in the tubing and also shows a device for forming the tubing from a single flat strip of flexible material, for example cellophane. The device comprises a wedge shaped member 93 which is mounted by means of a support 94 on a fixed part of the apparatus. A heated sealing member 95 co-operates with the upper side of the member 93. A groove 96 is formed in the undersurface of the member 93 across its width and disposed opposite the groove is the wire of a hot wire cutter 97.

As the flat strip 98 is fed over the member 93 it is folded around it so that its two longitudinal edges overlap and are continually sealed together by the sealing member 95 to form a flattened tubing having a single seam 99. Each time the tubing is stationary the hot wire of the cutter 97 is moved into the groove 96 and thus forms a transverse slit 100 across one face of the flattened tubing.

It will be appreciated that many modifications may be made to the arrangement described above without departing from the scope of the invention. For example other known forms of device may be used for sealing and cutting the tubing. For example a laser may be employed for cutting the tubing.

Also other means may be employed for opening out the flattened tubing whilst each transverse slit is formed.

For example, instead of there being a member disposed within the tubing to expand it, suction devices may be employed outside the tubing to open the tubing out.

I claim:

1. A method of forming filled bags from a continuous length of flexible tubing which is initially in a flattened state, comprising the steps of flattening successive portions of the tubing in a plane substantially at right angles to its initial plane, forming slits in the tubing by severing both opposed walls of each flattened portion along a line extending from one longitudinal edge of the flattened portion to a point intermediate of its longitudinal edges, reflattening the portions in their initial plane so that at least the major part of each slit lies in one wall of the re-flattened tubing, sealing the tubing across its width at a succession of locations alternating with the slits so as to provide a bag portion to one side of each slit and between that slit and a sealed part of the tubing, introducing the required contents through each slit into each bag portion, and sealing the tubing across its width on that side of each slit nearer the first sealed part whereby the contents are sealed within each said bag portion.

2. A method according to claim 1 and comprising the further step of severing each filled and sealed bag from the length of tubing.

3. A method according to claim 1 wherein the tubing is fed intermittently stopping temporarily at a succession of stations, each of said steps being performed at a different station when the tubing is temporarily stationary.

4. Apparatus for forming filled bags from a continuous length of flexible tubing which is initially in a flattened state comprising: means for feeding the flexible tubing through the apparatus; means for flattening successive portions of the tubing in a plane substantially at right angles to its initial plane, means for severing both walls of each flattened portion along a line extending from one longitudinal edge of the flattened portion to a point inter mediate its longitudinal edges to form a slit, means for re-flattening the tube portions in their original plane so that at least the major part of each slit lies in one wall of the re-flattened tubing; means for sealing the tubing across its width at a succession of locations alternating with the slits so as to provide a bag portion to one side of each slit and between that slit and a sealed part of the tubing; means for introducing the required contents through each slit into each bag portion; and means for sealing the tubing across its width on that side of each slit nearer the first sealed part, whereby the contents are sealed within each said bag portion.

5. Apparatus according to claim 4 wherein said means for flattening successive portions of the tubing in a plane substantially at right angles to its initial plane comprises a member disposed within the tubing and shaped to support a portion of the wall of the tubing in a position out of contact with any other part of the wall, and wherein said severing means is adapted to form a slit in said portion of the wall of the tubing.

6. Apparatus according to claim 5 wherein said member is formed with a rebate and said portion of the wall of the tubing bridges said rebate.

7. Apparatus according to claim 5 wherein said member is floating within the tubing said apparatus further comprising fixed bearing elements outside the tubing for restraining said member against movement with the tubing.

8. Apparatus according to claim 7 wherein the tubing is moved upwardly and the weight of the floating member maintains it in position within the tubing.

9. Apparatus according to claim 4 wherein the means for flattening a portion of the already flattened tubing in a plane substantially at right angles to its original plane comprises a first member disposed within the tubing and shaped to expand the tubing in a direction substantially at right angles to its original plane as it passes over said first member thereby flattening the tubing in a plane at right angles to said original plane, and wherein the means for re-flattening said tube portion in its original plane comprises a second member disposed within the tubing and shaped to expand the tubing in a direction substantially parallel to its original plane.

10. Apparatus according to claim 9 wherein each of said first and second members is floating within the tubing and is restrained against movement with the tubing by fixed bearing elements outside the tubing.

11. Apparatus according to claim 10 wherein the tubing is moved upwardly over the floating members and the weight of the members maintains them in position within the tubing.

12. Apparatus according to claim 9 wherein said two members are connected together to form a unitary floating structure.

13. Apparatus according to claim 4 and further comprising blower means for directing a blast of air through each said slit to expand each bag portion whereby said contents may readily be introduced into each bag portion.

14. Apparatus according to claim 4 and further comprising means for stretching the tubing across its width adjacent each said slit before the tubing is sealed across its width on that side of each slit nearer the first said sealed part.

15. Apparatus according to claim 14 wherein said means for stretching the tubing across its width comprises a pair of finger members having means for moving the finger members toward and away from one another, means for moving said finger members toward the general plane of the tubing from one side thereof to introduce the finger members when they are disposed adjacent one another into each slit and to press flat the tubing on that side opposite each slit and means for separating the finger members in the direction of the width of the tubing while in the slit so as to stretch the tubing across its width adjacent the slit.

16. Apparatus according to claim 4 and further comprising cutter means for severing the filled bag portions successively from the length of tubing.

17. Apparatus for forming filled bags from a continuous length of flexible tubing which is initially in a flattened state comprising: means for feeding the flexible tubing through the apparatus; means for forming a succession of spaced transverse slits in a part of the wall of the tubing;

means for sealing the tubing across its width at a succession of locations alternating with the slits so as to provide a bag portion to one side of each slit and between that slit and a sealed part of the tubing; means for introducing the required contents through each slit into each bag portion; a pair of finger members mounted to one side of the flattened tubing; means for moving the finger member towards the general plane of the tubing to introduce the finger members into the slit and to press flat the tubing on that side of the slit remote from the sealed part of the tubing; means for separating the finger members in the direction of the width of the tubing while in the slit so as to stretch the tubing across its width adjacent the slit; and means for sealing the tubing across its width on that side of each slit nearer the first sealed part, whereby the contents are sealed within each said bag portion.

18. Apparatus according to claim 17 wherein said finger members are carried on an assembly pivotally mounted to one side of the tubing so that pivoting of the assembly movessaid finger members towards the general plane of the tubing and into the slit.

19. Apparatus according to claim 17 further comprising a bar which extends parallel to the general plane of the tubing and is mounted to pivot about an axis spaced from and parallel to the bar, said finger members being slidably mounted on said bar and means for sliding the fingers apart on the bar to stretch the tubing across its width adjacent the slit after the bar has been pivoted to introduce the finger members into the slit.

20. Apparatus according to claim 19 further comprising a third finger member fixed to said bar between said pair of slidable finger members to maintain the tubing to one side of the slit pressed flat while the slidable finger members on opposite sides of the third finger member stretch the tubing adjacent the slit on the other side thereof.

21. Apparatus for forming filled bags from a continuous length of flexible tubing which is initially in a flattened state comprising means for feeding the flexible tubing upwardly through the apparatus, means for forming a succession of spaced transverse slits in one part of the tubing wall, a floating member disposed within the tubing to support said part of the tubing Wall in a position out of contact with any other part of the Wall, said floating member comprising a lower portion of substantially V-shaped cross-section as seen in a direction at right angles to the length 'of the tubing and an upper portion defining a cavity adjacent said one part of the tubing wall for receiving said means for forming transverse slits as it passes through said one side of the tubing into the tubing, fixed bearing elements outside the tubing for restraining said floating member against downward movement, means for sealing the tubing across its width at a succession of locations alternating with the slits so as to provide a bag portion to one side of each slit and between said slit and a sealed part of the tubing, means for introducing the required contents through each slit into each bag portion, and means for sealing the tubing across its width on that side of each slit nearer the first sealed part whereby the contents are sealed within said bag portion.

References Cited UNITED STATES PATENTS 2,099,257 11/1937 Bergstein 53-177 X 2,612,738 10/1952 Salfisberg 53-183 X 3,200,563 8/1965 Berghgracht 53-373 3,269,087 8/1966 Cloud et al 53-183 THERON E. CONDON, Primary Examiner R. L. SPRUILL, Assistant Examiner U.S. C1. X.R. 53-183