US3471993A - Tilting bag forming and filling machine - Google Patents

Description

Oct. 14, 1969 c. E. MoNsL-:Es ET AL 3,471,993

TILTING BAG FORMING AND FILLING IVACHIEl Filed sept. 22, 19e? Z Ls a i 5 Sheets-Sheet l OCL 14, 1969 Q EI MQNSEES ET AL 3,471,993

TILTING BAG FORMING AND FILLING MACHINE Filed Sept. 22, 1967 5 Sheets-Sheet 2 INVENIORl CmuE E MM5/s55 WML/Am H. MCCALL BY v TTORNEYS Odi. 14, 1969 C, E, MQNSEES ET AL 3,471,993

TILTING BAG FORMING AND FILLING MACHINE 5 Sheets-Sheet 3 Filed sept. 22, 1967 INVENTORS Cmuas Ma/vsEEs WML/AM H MCC/:LL- f//ffwd/ATTORNEYS C. E. MoNsx-:Es ET AL TILTING BAG FORMING AND FILLING MACHINE Oct. 14, 1969 5 Sheets-Sheet 4 Filed sept. 22, 1967 su. w ME@ E C N WwM R E0. 0 WMH W I A .bm/r Eu wn. MwY C B Oct. 14, 1969 c. E.. MoNsEEs ET AL 3,471,993

TILTING BAG FORMING AND FILLIING MACHINE 5 Sheets-Sheet Filed Sept. 22, 1967 INVENTORS CLAUDE E Man/555s United States Patent O 3,471,993 TILTING BAG FORMING AND FILLING MACHINE Claude E. Monsees and William H. McCall, Durham,

N.C., assignors to Wright Machinery Company, Inc.,

Durham, N.C., a corporation of North Carolina Filed Sept. Z2, 1967, Ser. No. 669,797 Int. Cl. B65b 43/08, 51/30 U.S. Cl. 53-180 7 Claims ABSTRACT F THE DISCLOSURE A tube former pivoted on a horizontal axis for swinging in a vertical plane and a drawbar pivoted on a second horizontal axis for swinging in the same vertical plane. The drawbar carries movable sealing and clamping jaws for drawing tube forming material through the former as the drawbar swings. A guide rod is xed to the former and is slidable through a pivoted bushing on the drawbar to cause the former to swing so as to keep its centerline always pointed toward the jaws on the drawbar. A springtensioned belt is guided between the tube former and drawbar in position to support a formed and filled tube as the centerline swings from an upright position toward the horizontal. A dolly or carriage, separate from the tube forming machine, carries a roll of heat sealable tube forming web material and is rollable over the floor to and from a position where the roll is properly aligned to feed such material to the tube former. A brake on the dolly maintains proper tension in the material being withdrawn from the roll and guiding and positioning means on the machine frame guide the dolly into proper position relative to the machine.

Background of the invention This invention relates to bag forming and filling machines wherein a length of heat scalable film or web material is drawn through a tube former, heat-sealed longitudinally to form a tube and cross-sealed at intervals in sequence with placing of charges of material in the formed tube. Machines of this general type have been known heretofore wherein a strip of material is fed through a tube former and drawn therethrough by cyclically operable sealing jaws which close on the material below the tube former to form a cross-seal, then move away from the tube former to draw material therethrough. A weighed charge of material is then dropped through the former into the tube above the crossseal and the previously filled tube section is cut olf whereupon the jaws are then opened, moved toward the tube former, again closed on the tube above the charge of material and the cycle is repeated. Machines of this general type are disclosed in the patent to Tew 2,953,882 and the patent to Tew et al. 3,256,673.

In the machines of the prior art it has been customary to provide material weighing and dumping means above a fixed tube former and to draw the tube material through the former in a substantially vertical direction. Heretofore this system has proven satisfactory but in recent times it has become desirable to package such materials in larger bags, considerably longer than those heretofore contemplated. For example, it is often `desirable to package potato chips in bags of greater length than is practical with machines of prior art. To construct machines of the known type with sufficient Vertical capacity to accommodate the longer bags would result in a machine of such height, when considering also the weighing and dumping mechanism thereover, that many plants would be unable to use such machines, not having sufficiently Lll) ICC

high ceilings and such machines would be uneconomically large and bulky.

Summary of the invention The above-noted disadvantages of the prior types of machines have been overcome by the present invention wherein unusually long Vbags can be formed and filled in a machine of minimum height and extreme compactness. The basic principles of the invention reside in the provision of a tube former that is pivoted for swinging moyement in a vertical plane and a drawbar assembly on A'which the sealing and pulling jaws are reciprocably mounted with the drawbar assembly being pivoted on a second horizontal axis so that the drawbar swings in the same vertical plane as the tube former. Means interconnecting the tube former and drawbar ensure that they will tilt in unison with the axis of the tube former always pointing toward the region of the jaws on the drawbar and thus assure that the tube forming material will always be drawn straight through the former. The parts are so arranged that the drawbar swings from a generally horizontal position below a generally upright tube former to a position where it is substantially vertical and displaced horizontally a relatively large distance from the tube former. By this arrangement an unusually long bag can be drawn through the tube former even though the parts are initially quite close to the iloor. The arrangement also permits the positioning of a product weighing and dumping mechanism at a level somewhat below the top of the machine and thereby further reduces the overall height of the apparatus. A further feature of the invention resides in the provision of a separate carriage or dolly for transporting and positioning supply rolls of bag forming material. With the bags of the large size contemplated here, the rolls of material are quite large and heavy and diflicult to manipulate if necessary to position them on the machine itself. By mounting the rolls on a separate dolly, applicant can load rolls of material thereon at a convenient location and by using power equipment, if desired, whereupon the dolly can be rolled into position relative to the machine wherein the roll is in proper alignment with guiding means for directing the material to the tube former. The machine and dolly are provided with cooperating means to elfect guidance of the dolly to the proper position and for holding same there during operation.

Brief description of the drawings FIG. 1 is a side elevational View of the packaging machine of the present invention;

FIG. 2 is a horizontal fragmentary sectional view taken on the line 2 2 of FIG. l;

FIG. 3 is a diagrammatic vertical section of the packaging machine of FIG. l showing the principle elements of the machine actuated to the package delivery position;

FIG. 4 is an enlarged fragmentary sectional View taken along line 4 4 of FIG. 1;

FIG. 5 is an enlarged fragmentary vertical sectional View, taken on the line 5 5 of FIG. 4;

FIG. 6 is an enlarged fragmentary sectional view of the tube forming assembly, taken on the line 6 6 of FIG. 1;

FIG. 7 is an enlarged horizontal sectional view taken on the line 7 7 of FIG. l, diagrammatically showing the driving arrangement and its component parts;

FIG. 8 is an enlarged plan view 0f the dolly or carriage assembly, partly in section, taken on the line 8 8 of FIG. 1; and

FIG. 9 is an enlarged vertical sectional View, taken on 3 the line 9 9 of FIG. 8 showing the braking arrangement for the supply roll.

Description of the preferred embodiment Referring rst to FIGS. 1 and 3, the machine of the present invention comprises a frame generally designated at 2, having thereon a tube former 4 mounted on a subframe 6, which in turn is pivotally mounted about a horizontal axis by pivot pins 8, on the machine frame 2. The tube former 4 may be of known construction, for example, like that shown in the patent to Monsees et al. 2,940,408. A drawbar assembly 10 is pivotally mounted by means of a shaft 12 on the frame 2 of the machine and, as shown, is generally L-shaped and comprises a lower drawbar portion 14. Suitable driving means are provided in the upper portion 15 of the machine and will be described in greater detail later but which include a crank 16 connected through connecting rod 18 to the drawbar assembly 10. Thus, as the crank rotates the drawbar assembly will cyclically swing between the positions shown in FIG. 1 and FIG. 3.

Guide rods 20 are fixed relative to the tube former 4 by being fixedly mounted on the sub-frame 6 and extend parallel to but spaced from the axis of the tube former 4 toward the drawbar assembly and slidably through a bushing 22 pivotally mounted on the drawbar portion 14 by suitable pivot means 24. As will be apparent from a comparison of FIGS. 1 and 3, the tube axis of the tube former 4 is thus constrained to always extend toward substantially the same point on the drawbar portion 14.

Suitable sealing and clamping jaw assemblies 26 and 28 are slidably mounted on the drawbar portion 14 for movement toward and from each other, in a manner that will be described in greater detail later. A pneumatic motor 30 operates through mechanism to be described, to move the jaw assemblies 26 and 28 toward and from each other, operation of the pneumatic motor being controlled by a timing or program shaft to be referred to later. The mechanism also includes a cutting knife on the jaw assemblies 26 and 28 and which operates in response to swinging movement of the drawbar assembly to cut off a filled and sealed tube, as will be further described.

A flexible belt 32 of substantial width has one end fixed to the sub-frame 6i in a position to extend therefrom generally tangent to and longitudinally of the hollow tube drawn through the former 4. That belt extends from the sub-frame 6 over a lirst guide roller 34 on the movable jaw assembly 26, then over a second guide roller 36 on the jaw assembly 26, then over a further roller 38 journalled at the outer end of the drawbar portion 14. From there the belt 32 extends over a fixed roller 40 on the machine frame to where its other end is secured to an end of a cantilever spring assembly 42. The spring assembly 42 is biased as to constantly apply tension to the belt 32 to pull its lower end downwardly toward the oor 44. The direction and ararngement of belt 32 is clearly evident in FIG. 1 and illustrates the shape assumed by that belt when the parts are in a starting position, at the beginning of a cycle of operation. As the drawbar assembly is swung clockwise toward the position of FIG. 3, the belt will eventually leave the roller 38 on the end of the drawbar and extend directly form roller 36 to the cantilever spring assembly 42, as shown in FIG. 3. The parts are so proportioned that swinging movement of the drawbar assembly between the two extreme positions shown will merely cause the cantilever spring assembly 42 to llex downwardly, then upwardly, thus maintaining the belt 32 at all times taut and in a position to support a formed and lled tube portion 46 (FIG. 3) to extend directly outwardly in alignment with the tube former 4 and toward the region of the jaws 26 and 28.

FIG. 1 shows the parts at the start of a cycle of operation. The jaw assemblies 26 and 28 are in their po .4 sition of nearest approach to the tube former 4 and have just been closed to form a cross-seal on the tube above a charge of material previously placed in the lowermost tube portion 48 to thereby seal that lower bag portion. The drawbar assembly then is caused to swing clockwise by crank 16, to the position of FIG. 3, and during this swinging movement, the jaw assemblies 26 and 28 forcibly draw tube forming material through the former 4. During such drawing movement, a fixed cam 50 actuates a lever 52 on the drawbar assembly to reciprocate a knife to sever the tube between the edges of the cross-seal so as to separate the lower filled bag 48 from the tube material thereabove. However, since the jaws remain closed during this drawing movement, the bag 48 is not dropped until it reaches the position of FIG. 3 wherein the jaws 26 and 28 are moved to the open position, thus releasing the bag 48 to slide oi a supporting tray 54 onto suitable receiving means.

The supporting tray 54 is pivotally carried by the drawbar portion 14 for free pendulous suspension therebelow. In the position shown in FIG. 1, the tray 54 engages the belt over the roller 40 to hold the tray in that position wherein the bag 48 is held in alignment with the axis of the tube former 4. Other fixed stop means may be employed, if desired. When the drawbar assembly swings toward the position of FIG. 3, the tray 54 is permitted to drop toward the position shown in FIG. 3 wherein it engages a stop bracket 56 carried by the drawbar portion 14 and thus properly directs the completed bag 48 onto the receiving means.

After the jaw assemblies 26 and 28 have been moved to their open position, as shown in FIG. 3, the drawbar assembly starts to swing counterclockwise back to the position of FIG. 1. The formed tube portion 46 depending from the tube former rests on :and is supported by the belt 32.

While the parts are in the position shown in FIG. 3, a suitable product-weighing mechanism operates to weigh and isolate a charge of material, which is then dropped into a charge pan 58 extending generally horizontally from the upper open end of the tube former 4, in the position of FIG. 3. Although the weighing mechanism drops a charge of material into the pan 58 at this time, it does not move through the tube former until the drawbar starts to swing counterclockwise, thus tilting the tube former counterclockwise until material can ow by gravity from the pan 58 into the formed tube portion 46. This flow of product starts while the tube former is still at a substantial angle from the horizontal and thus relieves the hot cross-seal 60 of the direct weight of the product and relieves it of lany 'impact therefrom since the product merely slides rather gently along the entire length of the formed tube to a position of rest against cross-seal 60. The weight of the product is not completely supported by the cross-seal 60 until the parts reach substantially the position of FIG. 1 and sufficient time has elapsed for the heat-sealed material of the bag to cool sufficiently to provide a strong cross-seal at 60. While the charge of material moves into the formed tube, the jaws 26 and 28 are separated and move upwardly along opposite sides of the tube and product until they reach the position in FIG. l, above the charge of product whereupon the cycle is repeated.

As previously described, the guide rods 20 are fixed relative to the sub-frame 6, which supports the tube former 4. Two such guide rods are provided, one on each side of the machine, as shown in FIGS. 4 and 6. The guide rods 20 are lixedly mounted in brackets 62 constituting fixed portions of the sub-frame 6. As shown in FIG. 6, the subframe 6 is journalled on pivot pins 8, carried by brackets 64, which in turn :are secured to frame members 2. The guide rods 20 extend upwardly from the sub-frame 6 and support a further bracket `66 to which a hollow mandrel device 68 is secured. The mandrel device extends downwardly into the tube former 4 and the tube forming material passes between the tube former and the mandrel in a known manner. The mandrel 68 also constitutes at least part of a back-up structure against which a heated shoe 70 presses the overlapping edges of the tube forming material to form a longitudinal seal along the formed tube -as the material is drawn, also in a well known manner. The heated shoe 70 is also supported from structure 71 mounted on the guide rods 20, At their upper ends the guide rods 20 are provided with a further bracket 72 which supports the hopper or charge pan 58, previously referred to, and which in turn is provided with an outlet or spout 74 for directing material therefrom into the interior of the mandrel 68. The details of the longitudinal sealing shoe 70 and its supporting structure will not be described in any greater detail herein.

Referring now to FIG. 2, the cantilever spring assembly 42 comprises a crossbar 76 fixed to frame elements 2 and to which one end of the cantilever leaf springs 718 is secured. The other ends of the leaf springs 78 are secured to a crossbar 80 to which the lower end of the belt 32 is attached. Preferably, the machine frame includes side plates 82 defining an enclosure within which the cantilever leaf spring assembly may ex without interference from external objects.

Referring now to FIG. 7, schematically showing a driving arrangement as provided in the upper portion 15 of the machine frame, a suitable motor 96 provides power for the machine and drives a belt 94 to an electric clutch and brake 84 and from there through a gear boxl 86 which rotates an output shaft 88 on which the crank 16 is fixed. The gear box 86 also drives, through bevel gears 90, to a timing 4and program shaft only schematically shown at 92. It is contemplated that the sh-aft 92 be provided with suitable cams for actuating valves, switches and the like to effect proper timed relation of different functions of the apparatus.

Referring again to FIG. l, the crank 16 comprises a block portion 98 fixed to shaft 88 and in which a crank arm 100 is adjustable to vary its length. At its outer end the crank arm 100 is provided with releasable clamping means 102 pivoted thereto whereby it may be adjusted along the length of connecting rod 18. Thus,'both the effective length of connecting rod 18 and of the crank arm 100 may be adjusted. By :adjusting the length of crank arm 100, the total `angular movement of the drawbar assembly can be preset to any desired value, within the capacity of the machine. That is, the total swing of the jaw assemblies 26 and 28 may be predetermined in accordance with the desired length of bag material to be drawn through the former 4 yat each cycle of operation. It is, of course, desirable that the severing and release of the sealed and filled bag 48 always be completed :at the same point in the machine, which means that the drawbar portion 14 should always be in the vertical position shown in FIG. 3, at the end of each cycle irrespective of the length of bag for which the machine is set. Thus, by adjusting the length of crank :arm 100, the length of the bag may be predetermined and then by adjusting the length of the connecting rod 18, the terminal position of the drawbar may be regulated so that it always occurs in the position shown in FIG. 3.

Referring now to FIGS. 4 and 5, the drawbar assembly is shown as being of substantial lateral width andas comprising two generally L-shaped side plates 104. The side plates 104 are rigidly secured together by a plurality of cross members, such as shown at 106, and the assembly is journalled on the shaft 12 previously referred to and which extends between opposed frame members 2. Also journalled between the side plates 104 is an actuator shaft 108, appearing directly below shaft 12 in FIG. 4. The pneumatic motor 30 previously referred to comprises a. cylinder pivotally carried by a bracket 110 on the drawbar assembly and having a piston therein, with a piston rod 112 extending downwardly therefrom into operative connection with a crank arm 114 fixed on the shaft 108.

Outer crank arms 116 (FIG. 4) are fixed to the outer ends of shaft 108 and extend generally rearwardly therefrom. Connecting rods 118 connect the crank arms 116 to the outermost movable jaw assembly 26. Between the plates 104 a second pair of crank arms 120 is fixed to the shaft 108 to extend forwardly therefrom and which are connected, by connecting rods 122, to the innermost movable jaw assembly 28. The jaw assemblies 26 and 28 are slidably guided for movement toward and from each other on suitable guide rails or rods 124. It will thus be seen that actuation of the pneumatic motor 30 to extend its piston rod' 112 downwardly will cause shaft 108- to rock clockwise, as seen in FIG. l. This will result in the connecting rods 112 drawing jaw assembly 28 inwardly and connecting rods 118, pushing jaw assembly 26 outwardly, so as to separate the jaws. Obviously, as the pneumatic motor 30 is operated to Withdraw its piston rod 112 upwardly, shaft 108 is rotated counterclockwise to move jaw assemblies 26 and 28 toward each other.

The jaw assemblies 26 and 28 are shown in somewhat greater detail in FIG. 5. As shown, each of the heated jaw portions 126 is formed to define two spaced heating bands for cross-sealing the tube of material. A knife 128 is rotatably mounted in a slot 130 in the jaw on assembly 28 and that knife is reciprocated outwardly of the jaw by a rod 132 connected to a lever 133 which is pivoted at 134 to the jaw assembly 28. A spring 136 normally urges a connecting rod 138, which in turn is pivotally connected to the upper end of lever 132, to move to the right, as seen in FIG. 5, and thus draw the knife 128 inwardlyof the slot 130. The connecting rod 138 is connected to the bell crank lever 52, previously referred to. Each of the heated jaw portions 126 may be of known or conventional construction, including electrical heating elements 140 therein providing the heat necessary to maintain the jaws hot enough to effect heat sealing of the tube material.

Below the jaw portion 126 on jaw assembly 28 is a fixed stripper bar 142, having an edge portion 144 projecting forwardly slightly beyond the bag engaging face of the' jaw portion 126. A second stripper bar 146 is mounted on the jaw assemblyv 26 and is spring urged, by springs 148, toward the stripper bar 142 and to a position where its inner edge projects beyond the sealing face of its associated heated jaw portion 126.

At the start of a cycle of operation and when the pneumatic motor 30 is operated to project the jaw assemblies toward each other, it will be obvious that the stripper bars 142 and 146 engage the sides of the formed tube prior to engagement thereof by the heated jaws. The shaft 108 is provided with a cam 150 (FIG. 4), which is configured to actuate a switch or other suitable mechanism to stop the jaw assemblies 26 and 28 while the heated jaws are still separated but after the stripper bars 142 and 146 have flattened and engaged the formed tube above the charge of product therein. This spacing of the jaws is maintained during the initial swinging of the `drawbar assembly 10 so that the stripper bars will strip any stray particles of product from the region to be engaged by the heated sealing jaws so that such particles will not be trapped between the jaws during the heating cycle. At the desired time in the cycle of operation the timing or program shaft 92 will operate a suitable valve or valve control to again actuate pneumatic motor 30 to completely close the heated jaws on the formed bag, thereby heat sealing the same and gripping the same so that further movement -of the drawbar assembly will draw tube forming material through the former 4 as already` described.

Referring now to FIGS. l, 8 and 9, the tube former 4` roll 154 the material passes over and around suitable guide and directing rollers on the dolly, which will be described later, then over a first guide roll 158 on the machine frame 2 from which it is directed over suitable rollers 160, 162 and 164 and then upwardly to guide rollers 166 on the sub-frame 6. From the rollers 166 the material is directed to the receiving and web guiding portion 167 of the tube former 4. Also mounted on the sub-frame 6 is a pneumatically operated brake, designated generally at 168, for applying a restraining force to the web 152. From the previous description it will be apparent that cyclical operation of the machine causes the tube former 4 and the sub-frame 6 to swing about the horizontal axis defined by pivots 8. During that swinging movement the guide rollers 166 move toward and from the fixed guide roller 164 and thus alternately introduce slack and tension into the web. The brake -168 is provided to prevent any slack or looseness from appearing at the tube former 4, since it is necessary to keep the material in snug contact therewith at all times.

As shown, the roller 162 is adjustable in a vertical direction whereby to change the length of material of the web between the supply roll 154 and the tube former. Such adjustment is sometimes necessary to properly correlate printed material on the web to appear between the cross-seals ultimately formed on the filled packages.

The carriage or dolly 156 comprises a suitable framework having floor engaging supporting wheels 170, one of which is a caster wheel, whereby the dolly can be freely moved over the floor 44. Opposed end plates 172 are provided with aligned notches 174 constituting supporting means for a shaft 176 which in turn supports the roll 154 of web material. The web material 152 is wound on a hub member 176.

The dolly or carriage 156 is provided with a handle 178 by which it may be manually manipulated and is also provided with grooved rollers 180, extending outwardly from one side thereof. The machine frame 2 is provided with a fixed rail 182 thereon at such elevation and in such position that manual movement of the dolly toward the illustrated relationship to the machine causes the rollers 180 to engage and be guided by the track 182 so as to properly orient the supply roll 154 parallel to the roller 158 on the machine frame. The track 182 is further provided with a stop 184 at the inner end thereof (see FIG. 8) and when the forward roller 180 engages the stop 184, an abutment or screw 186 is placed in an appropriate opening in the track 182 outwardly of the rear roller 180 to thereby positively hold the dolly in the proper lateral position relative to the machine. In view of the capacity of the machine of the present invention and its ability to produce larger and longer bags than heretofore made, a supply roll of web material must necessarily be rather large to produce a reasonable number of bags without replacement. The rolls 154 are thus quite large and heavy and impractical to manipulate for positioning on supporting means constituting a part of the machine itself. By the use of the dolly or carriage 156, power equipment may be employed to position a supply roll on the dolly at a location remote from the bag forming machine and it is then easy to move the supply roll into the described position for directing the web to the tube former.

Further structural details of the carriage or dolly 156 are shown in FIGS. 8 and 9 wherein a friction brake 188 is shown pivotally mounted on one of the end plates 172 of the dolly, by means of a suitable pivot 190. The friction brake 188 is in position to engage the periphery of the hub or mandrel 176 on which the roll 154 is wound and the web 152 is directed from the roll 154 upwardly and over a guide roller 192 on the dolly, then downwardly and around a roller 194 journalled on a movable frame 196. From the roller 194 the web is directed upwardly to the guide roller 158 on the machine frame. The movable frame 196 is fixed to a shaft 198 which is in turn j'ournalled between the end plates 172 of the dolly and which carries a crank arm 200 depending therefrom. A connecting rod or link 202 is pivoted at one end to the crank arm 200 and at its other end is pivoted to the lower end of lever 204, which is itself pivoted to end plate 172 on a suitable pivot 206. An intermediate portion of the lever 204 is connected to the upper end of the friction brake 188 by a link 206. A spring 208 abuts at one end against an adjustable stop means 210 fixed on the rod 202 and abuts at its other end against bracket 212 fixed to the frame of the dolly 156. Thus, through the link 202, crank arm 200, shaft 198, and movable frame 196, the roller 194 is resiliently urged downwardly, tending to apply tension to the web 152. As web material is drawn into the tube forming machine, it exerts an upward force on the roller 194 and against theaction of spring 208. Any movement of the rod 202 in response to a change of tension in the web will swing the lever 204 to regulate the pressure applied by brake 188 to the hub of mandrel 176. As is obvious, an increase in the tension of the web 152 will tend to relieve the pressure of the brake 188, which in turn permits the roll 154 to turn more freely and reduce tension in the web 152. The abutment 210 may be adjustable on the rod 202 to thus regulate the force exerted by spring 208 and predetermine the magnitude of the tension in the web and tend to maintain the same substantially constant. Furthermore, when the tube former and sub-frame 6 swing about pivot 8 in a direction toward guide roller 164, the tension in the web between guide roller 164 and the roll 154 would normally be relieved and slack or looseness would be introduced. Reversal of the swing ing movement of the tube former would apply sudden shock to the web 152 and due to the high inertia of roll 154, damage to the web or misalignment thereof could result, Hence, when such slack develops due to the normal operation of the machine, the brake 188 will become set to prevent rotation of the roll 154 until the desired tension is again developed in web 152.

While a single specific embodiment of the invention has -been shown and described herein, it is to be understood that the same is merely illustrative of the principles involved and that other embodiments may be resorted to within the scope of the appended claims.

We claim:

1. In a packaging machine having a tube former, means for guiding a continuous web of material generally downwardly through said tube former along a tube axis to form a longitudinally sealed tube, and cyclically operable means for forming a transverse seal across said tube and for drawing a predetermined length of material through said tube former, the improvement comprising: means mounting said tube former for swinging movement in a vertical plane about a first axis; means mounting said cyclically operable means for swinging movement in said vertical plane, about a second axis; and control means interconnecting said tube former and cyclically operable means for causing simultaneous swinging movements thereof.

2. A machine as defined in claim 1 wherein said lastnamed means comprises an elongated guide member fixed relative to one of said tube former and cyclically operable means and slidably engaging a guide element on the other.

3. A machine as defined in claim 1 wherein said first axis extends substantially through said tube axis at said tube former; said second axis being laterally spaced from said first axis and at an elevation at least equal to that of said first axis; said cyclically operable means comprising a rigid structure including a drawbar portion extending across said tube axis below said tube former and sealing and clamping jaws slidably mounted on said drawbar portion on opposite sides of said tube axis for movement toward and from each other.

4. A machine as defined in claim 3 wherein said control means comprises at least one rigid guide rod iixed to said tube former and extending therefrom, parallel t0 said tube axis, and slidably through a guide bushing pivotally mounted on said drawbar portion.

5. A machine as delined in claim 1 including a flexible supporting means extending between said tube former and said cyclically operable means, spaced from but adjacent said tube axis; and tensioning means for holding said flexible means taut.

6. A machine as defined in claim 3 including a machine frame and a llexible belt having one end thereof secured to said tube former and extending, in substantially tangent relation to said formed tube, over guide rollers on said drawbar then to tensioning means on said frame, said belt being arranged to be below said formed tube as said tube former swings in said vertical plane whereby to sup port the weight of said formed tube and any contents therein.

7. A machine as defined in claim 1 including drive means for swinging said cyclically operable means in said vertical plane, said drive means comprising a drive crank; means for adjusting the throw of said crank; a connecting rod drivingly connecting said crank to said Vcyclically operable means; and means for adjusting the effective length of said connecting rod.

References Cited UNITED STATES PATENTS THERON E. CONDON, Primary Examiner E. F. DESMOND, Assistant Examiner

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