US2840961A

US2840961A - Method and apparatus for producing evacuated packages

Info

Publication number: US2840961A
Application number: US524750A
Authority: US
Inventors: Jr Benjamin Karpowicz
Original assignee: PAK RAPID Inc
Current assignee: PAK RAPID Inc; PAK-RAPID Inc
Priority date: 1955-07-27
Filing date: 1955-07-27
Publication date: 1958-07-01
Anticipated expiration: 1975-07-01

Description

July 1, 1958 B. KARPOWICZ, JR

METHOD AND APPARATUS FOR PRODUCING EVACUATED PACKAGES 5 Sheets-Sheet 1 Filed July 27. 1955 Qua. ATTO R N EY5 1958 B. KARPOWICZ, JR 2,840,961

METHOD AND APPARATUS FOR PRdDUCING EVACUATED PACKAGES Filed July 27. 1955 5 Sheets-Sheet 2 1% WW maraw ATTORNEY5 July 1, 1958 B. KARPOWICZ, JR 2,840,951

METHOD AND APPARATUS FOR PRODUCING EVACUATED PACKAGES Filed July 27. 1955 5 Sheets-Sheet s July 1, 1958 B. KARPOWICZ, JR

METHOD AND APPARATUS FOR PRODUCING EVACUATED PACKAGES Filed July 27 5 Sheets-Sheet 4 ATTORNEYS July 1, 1958 13,- KARPOWICZ, JR METHOD AND APPARATUS" FOR PRODUCING EVACUATED PACKAGES Filed July 27. 1955 5 Sheets-Sheet 5 W U 'TWIER RELAY TIMER "rm? swn'cmif NOZZLE soLzNomff A r TIMER CONTACTS CLUTCH SOLYLNOID77 cum "0496 VACUUM VALVE VACUUM VALVE swn-cu 95 souznom 54 ATTORNEYS METHOD AND APPARATUS FUR PRflD-UCENG EVAQ'UATED PACKAGEEE Benjamin Karpowicz, In, Philadelphia, P31. assignor to Pw-Rapid, ind, Fhiiadelphia, Pin, a corporation of Pennsylvania Application Early 27, 1955, Serial No. 52 5,75 3

20 Claims. Cl. Ha-22) My invention relates to a method of forming, filling, evacuating and sealing packages made from air tight flexible packaging material and to a particular type of apparatus or system to carry out the method.

There are two principal reasons for evacuating the packages, first to prevent deterioration of the packaged products by contact with air in the package and second to reduce the bulk of the packages so that they can be packed in a smaller space than that required for unevacuated packages.

in accordance with my invention opposed strips of packaging material are fed between opposed heat sealing rolls which seal the strips together at the edges and also form transverse or cross seals at intervals to form individual packages (which are later severed from the strip) for products which are deposited between the opposed strips during the formation of the package. Apparatus of this general type is illustrated in Lewis Patent No. 2,626,494 and my invention consists in the improvement in the method and apparatus which provides a system for evacuation of the'individual packages just before the package is completely sealed from the atmosphere by the completion of a transverse seal.

For illustration of my improved method and apparatus reference is made to the accompanying drawings wherein:

Figure l is a side elevational view of a packaging machine constructed in accordance with the invention;

Figure 2 is a plan view of the machine as indicated by the line 2-2 of Figure 1 with the top plate broken out and with a portion of an article feeding plate shown in dot and dash lines as is also the packaging material;

Figure 3 is a vertical cross section taken on the line 3--3 of Figure 2;

Figure 4 is a fragmentary plan section on the line l i of Figure 3;

Figure 5 is a rear elevational view looking toward the left in Figure 1;

Figures 6, 7, 8 and 9 are enlarged fragmentary sections showing various nozzle and roll positions during a cycle of operation;

Figure 10 is a fragmentary view looking toward the left in Figure 9 with the right hand roll of Figure 9 omitted;

Figure 11 is a plan section on the line 11l11 of Figure 9;

Figure 12 is an isometric view of a completed package;

Figure 13 is a fragmentary section showing a modification of the invention; and

Figure 14 is a schematic control diagram.

The machine comprises in general a pair of heated crimping and sealing rolls or dies R and R to which opposed sheets of packaging material P are fed from suitably supported rolls of the material (not shown), a supporting frame F for the heated rolls or dies R and R and for various associated mechanisms to be fully described hereinafter, a base. plate B on which the frame F is mounted, driving mechanism D for imparting inter- 2,840,961 Patented July 1, 1958 ice ' mittent rotation to the crimping and sealing rolls, and

means for creating a vacuum in the packages including a vacuum nozzle N and a vacuum pump and tank V of any well known form.

The packaging material may be any of several ma terials on the market adapted for the formation of airtight packages, such as a laminated polyethylene cellophane strip, a laminated kraft paper polyethylene strip, or a saran strip laminated to cellophane or kraft paper. The polyethylene and saran are thermo-plastic and when pressed together by the heated rolls R and R will form an air-tight bond between the opposed sheets of packaging material.

The products to be packaged are fed into the machine as by means of a rotary index plate having product receiving openings 21, adapted to be brought into registry with a guide chute ngxtending downwardly from the top frame member 23 into the V-shaped space between the runs of packaging material leading to the rolls R and R from the

guide rollers

24 and 25. In the drawings the articles being packaged are of rectangular form but it will be understood that irregularly shaped articles as well as pellets, liquids, etc. can be packaged.

The crimping and sealing rolls R and R are carried by

shafts

26 and 27 mounted in hearings in the frame F, the roll R being the driving roll and the roll R the driven roll. The bearings 28 for the driven roll are slidably mounted in slots 29 in the frame and the driven roll is urged into firm driving contact with the drive roll by means of springs 30. As seen in Figure 5 one end of the spring fill is connected to the frame F by a pin 31 and the other end to the bearing 28 by a pin 32. By means of this spring pressure the packaging material is tightly crimp sealed as it passes between the rolls by reason of the heat and pressure of the rolls. In order to prevent the rolls from getting out of phase loosely meshing

gears

33 and 34 are provided on the roll shafts.

As clearly seen in Figures 1, 2 and 3, the rolls R and R are each provided with cavities 35 for clearance of the pocket portions of the packages as the rolls rotate. In the apparatus illustrated each roll is provided with three cavities T15 of such size as to provide three equally spaced circumferential lands extending crosswise of the rolls and constituting cross seal members 36. Lengthwise of the rolls the cavities 35 end short of the sides of the rolls to provide axially arcuate webs or flange portions constituting side seal members 37. There is thus provided axially spaced circular surfaces on the rolls for forming edge seals for the packages and circumferentially spaced cross members for forming cross seals for the packages.

The rolls are peripherally serrated so. as to crimp the side seals and cross seals of the packages as they are formed, the side seals of a package being shown at 38, 38 in Figs. 1 and 12 and the cross or end seals at 39. The packages are formed in a strip for later cutting into individual packages at the cross seals as indicated by the line aa in Fig. 1. When cross seal 39 is cut a top seal is provided for one package and a bottom seal is provided for the adjacent package. Automatic knife mechanism of well known form may be employed for making the cut.

The packages may be heat sealed by means of electric heating elements carried by "the rolls which are supplied with electric current from a suitable source by means of contact rings 46 mounted on the roll shafts as shown in Figs. 1 and 2.

Referring now to the means for providing for the vacuum packaging of the product, it is to be noted that each of the cross seal members 36 of a pair of rolls has a groove or cut out portion 47 extending partially through the surface of the cross adjacent the webs at one. side of the rolls for accommodating the vacuum nozzle N. It will be noted that the grooves of each pair of cross seal members are in opposed position when the cross seals are being formed. Although it is preferable to provide grooves in each pair of cross seal members, it should be pointed out that it would be quite feasible to provide only one of a pair of the opposed cross seal members with the groove, provided such groove is large enough to accommodate the vacuum nozzle N.

The nozzle N is connected to the vacuum tank and pump V by a flexible hose and

passages

51 and 52 in the block 48. A valve 53 of any well known form is provided for controlling the connection to the vacuum tank. The valve 53 is actuated by means of a solenoid '54 and the nozzle N is actuated in its up and down movement by means of a solenoid 55 as will appear hereinafter.

Reverting now to the driving mechanism D for impart ing intermittent rotation to the rolls R and R and with particular reference -to Figs. 1, 2, 3 and 5 it will be seen that a ratchet wheel having three teeth is secured on the shaft 26 of the driving roll R and is driven by a pawl 61. The pawl is carried by one arm of a rock lever 62 mounted on the shaft 26, the other arm of which is connected to a crank arm 63 by a link '64. The crank arm 62 is adjustably mounted in a block 65 carried by crank shaft 66. The crank arm is rotated by means of a chain and sprocket connection 67 with a gear reduction unit 68 of standard form driven as by means of a belt l 69 drivingly connected to a suitable source of power such as an electric motor (not shown).

A one revolution clutch 70 of any well known form is disposed between the output shaft 71 of the reduction unit '68 and the driven shaft 72 carrying the sprocket '73 of the chain and sprocket connection 67. A stop latch 20 degrees short of the final driving position of the pawl.

Thus when thecrank arm 63 makes its next one revolution the pawl first drives the ratchet wheel and the rolls 20 degrees in driving direction and then as the crank arm continues in its rotation the pawl ratchets in nondriving direction and picks up the next tooth 75 of the ratchet wheel 60 to rotate it in driving direction to the point 74 where it again stops until the next release of the clutch. During the period of time that the pawl is in its back or non-driving stroke the rolls R and R remain stationary and it is during this period of time that the 57' product to be packaged may be delivered to the guide chute 22 for packaging in the next package to be formed.

It will be seen from the foregoing that the rolls have a double stop action for each cycle of the crank, the first stop being when the one revolution clutch completes its revolution and the pawl reaches the point 74 and the second stop being when the pawl reaches the point 26 degrees beyond point 74. i

I provide the double stop action in order to give a period of dwell (1) when the package is being evacuated and (2) when the transverse or cross seal is being completed. I believe this to be the preferable method to follow for forming an evacuated package for it takes a brief interval of time before the effective evacuation is completed and it is also desirable that there be a brief interval of time or period of dwell when the transverse seal is being formed in order to insure proper heating of the packaged material at the point where the transverse seal is formed by the cross seal members 36. It should be pointed out, however, that it is not essential that It is to be noted,

' rotate.

there be a period of dwell when the transverse seal is being completed.

It should further be pointed out that it is not necessary that the product to be packaged be delivered between the strips of packaging material during the period of dwell when the transverse seal is being completed and in fact it may be desirable if the product to be packaged is a liquid or in granular or pellet form, that it be delivered when the packaging material is moving during the period when the side seals are being formed.

The driven shaft 72 also carries a sprocket drivingly connected by chain 81 to a sprocket 82 on the cam shaft 83. The cam shaft 83 carries a cam 84 for actuating a switch 85 which is electrically connected to a timer S6 of known type including a timer mechanism with contacts under control of the time setting of the timer and a momentary contact controlled by the switch 85 for activating the timer.

In the position shown in Figure 5 the switch roller is riding on the high or dwell surface 87 of the cam 84 and the switch is open. It is pointed out that the low surface 88 of the cam is so located that the switch 85 closes when the pawl 61 of the ratchet drive D has moved approximately 20% of its up or driving stroke. Thus the clutch 70 in rotating to the position shown in Figs. 1 to 4- inclusive had closed the switch 85 to actuate the momentary contact of the timer '86 which in turn started the timer in motion for its pre-set time interval. Starting of the timer de-energizes the solenoid 55 to move the nozzleN to its down position and to close the vacuum control switch 95 and open the clutch latch control switch 96. Closing of the switch 95 opens the vacuum control valve 53 and opening of the switch 96 moves the clutch latch 76 to its stop position.

In this instance the time interval is set to operate the timer contacts to cause energization of the nozzle solenoid 55 a predetermined number of seconds after the clutch 70 has complete its revolution.

In Figs. 1 to 4 the solenoid 55 is shown energized. This solenoid is connected to the nozzle N by a link 90 and a lever 91 pivoted on the frame at 92. Thus with the solenoid energized the short arm 93 of the lever 91 is pulled down and the long arm 94 moves up to raise the nozzle from its down position shown in Figure 6 to its up position shown in Figs. 7-8 and 1 to 4. The upper switch 95 for controlling the valve 53 of the vacuum pump is associated with the short arm 93 of the lever 91 and the lower switch 96 for controlling the clutch '70 is associated with a lug 97 on the link 90. When the solenoid 55 is energized the arm 93 leaves the upper switch 95 to open the switch to de-energize the vacuum valve solenoid 54 and close the vacuum valve 53 thus cutting ofi the suction connection to the nozzle N. Next as the arm 93 moves downwardly the lug 97 of the link 90 engages the roller of the clutch control switch 96 to close it. Closing of this switch energizes the solenoid 77 which is connected by link 98 to the clutch stop latch 76 and moves the stop latch clear of the stop pin 99 of the clutch 70 to permit the clutch to In Figs. 3 and 5 the latch is shown so released and the clutch is ready to start rotating.

As has been pointed out above the clutch is so corelated to the ratchet drive mechanism D that in the first portion of the clutch rotation the pawl moves through 20 degrees of its up or driving stroke before it starts on its down or idle stroke. In moving this 20 degrees the rolls R and R are rotated to the position shown in Figure 8 in which the final portion of the cross seal is made. This provides a crimped cross seal across the entire width of the package of such extent that when a completed package is cut ofl a top seal is provided for that package and a bottom seal is provided for the next package. The cut should be made somewhat above the sealed slot 100 as shown in Figs. 1 and 12.

It is to be observed that since the time interval of the timer 86 has been set to operate the timer contacts a predetermined nuinlier of seconds enemas clutch has completed its revolution there will he a dwell of the rolls with the nozzle N in down position and with the suction on to provide ample time for creating a vacuum in the package. In drawing the vacuum, the exterior atmospheric pressure presses the packaging material closely around the nozzle as shown in Figs. 6 and 11 and in so doing the material at the slot is pre stretched to the shape of the nozzle so that when the nozzle is withdrawn the material tends to take its original fiat shape which in addition to the atmospheric pressure acting on the material and the tackiness of the material ensures a tight seal of the slot.

In Figure 13 a modification is illustrated in which silicon sponge rubber inserts 102 are provided in the grooves 47 to further. aid' in forming the material around the nozzle to provide a tight seal.

It will be seen from the foregoing that because of the particular disposition of the vacuum controlling switch 95 and the clutch latch controlling switch to. the sole! noid controlled lever 91 a particular and important sequence of nozzle withdrawal, vaciiurn 'shut ed and clutch release is maintained, namely after initiation of the nozzle withdrawal movement by the timer controlled solenoid 55, the switch 95 closes to shut off the vacuum and when the nozzle actuating lever 91 reaches the end of its nozzle lifting movement the clutch 70 is released to start rotation of the rolls R andR'. During the withdrawal movement of the nozzle outside atmospheric pressure acts on the material surrounding the nozzle to bring it together under the tip of the nozzle to seal the slot in a follow up action so that by the time the nozzle has reached the up position shown in Figure 7 the slot is fully sealed as shown in that figure. Since the. clutch is not released until after the nozzle is withdrawn to its. up position it is impossible for the nozzle to be pinched between the rolls when they rotate to their second stop position as will be clearly seen from inspection of Figure 8.

After the clutch has been tripped in the above manner the pawl moves in its driving direction through 20 degrees as above mentioned to similarly rotate the rolls to position to complete the cross seal and then the rolls dwell until the pawl has completed its return stroke and picked up the next tooth of the ratchet wheel 60. During this period of dwell the index feed plate 26 is rotated to deliver the next article into the chute 22 where it rests on the tapering runs 103-103 of the packaging material P. I

As rotation of the crank continues the pawl starts its upward or drive stroke and whenit has moved through approximately 28% of the upstroke the low portion 88 of the cam 84 causes the switch 85 to close and start the timer. As pointed out above, starting of the timer de-energizes the solenoid 55 which through means, of the link 90 and lever 91 causes the nozzle N to move downwardly into the package being formed to the position shown in Figure 9. When the solenoid is deenergized the link 90 in its upward movement causes the switch 96 to open thus de-energizing the solenoid 77 and moving the stop latch 76 into the path of the clutch pin 99. Also the short arm 93 of the lever 91 moves upwardly into contact with the roller of the switch 95 to close it. Closing of this switch energizes the electromagnet 54 to open the control valve 53 of the vacuum pump V thus establishing suction in the hose 50 leading to the nozzle and drawing a vacuum in the package. As this is taking place the rolls R and R continue to rotate until the stop pin 99 of the clutch engages the stop latch to stop rotation of the rolls in the position shown in Figs. 1 to 4 inclusive. This completes a cycle of operation and after the timer has run for its pre-set length of time the solenoid 55 is again energized t'o repeat the cycle.

The schematic diagram of Figure 14 indicates the timer trip switch 85 for the timer relay, the timer contacts forthe nozzle solenoid 55, the clutch switch 96 for the clutch solenoid 77 and the vacuum valve switch 95 for the vacuum valve solenoid 54.

By referring to Figure 12 it will be seen that the package is completely sealed around the edges and that with the air removed the packaging material fits the article snugly.

Insofar as the method of forming the evacuated package is concerned, it is not necessary that the movement of the packaging material be brought to a stop when the article to be packaged is delivered between the opposed strips of packaging material or when the cross seal is being formed. It is likewise unnecessary to stop the movement of the packaging material when the package is being evacuated, although in order to insure the most complete evacuation possible, a stoppage or at least a slowing down of movement of the packaging material at that time is preferable. The term interrupting movement of the material as used in the claims contemplated such a stoppage or slowing down of movement.

Although I have illustrated my invention as applied to an apparatus wherein there is but a single pair of rolls for forming the side seals and the end seals, it should be pointed out that side seals of strips of packaging material could be formed by separate rolls in advance of the rolls for forming the cross seals and my invention is not limited to an arrangement wherein there is but a single pair of rolls forming both the side and cross seals.

I claim:

l. A system for forming, filling, exhausting and sealing packages of flexible material comprisingopposed sealing rolls between which opposed strips of packaging material are fed and formed into packages, said rolls having axially spaced opposed circular surfaces for forming edge seals for the packages and circumferentially spaced opposed cross members for forming cross seals for the packages each cross member of a pair having a groove in a part of the surface thereof opposed to a like groove in the opposed cross member, a nozzle connected to a source of vacuum and adapted to project into said grooves, driving mechanism for said rolls and mechanism for controlling the operation of the rolls and of the nozzle including means providing a period of dwell for the rolls when the grooves of a pair of cross seal members are opposed and for thereafter causing said rolls to resume movement to complete formation of the cross seal and means operating to project said nozzle into the package in the region of said grooves and to withdraw it during said period of dwell, to evacuate the package.

2. A system according to claim 1 wherein the mechanism for controlling the operation of the rolls includes and thereafter causing said rolls to resume movement to means providing for a second period of dwell of said rolls during the completion of formation of the cross seal.

3. A system for forming, filling, exhausting and sealing packages of flexible material comprising opposed sealing rolls between which opposed strips of packaging material are fed and formed into packages, said rolls having axially spaced opposed circular surfaces for forming edge seals for the packages and circumferentially spaced opposed cross members for forming cross seals for the packages, at least one cross member of a pair having a groove in a part of the surface thereof, a nozzle connected to a source of vacuum and adapted to project into said groove, driving mechanism for said rolls and mechanism for controlling the operation of said rolls and of the nozzle including means providing a period of dwell for the rolls when the cross seal members are opposed complete formation of the cross seal and means operating to project said nozzle into the package in the region of said grooves and to withdraw it during said period of dwell, to evacuate the package.

I 2,840,9hi

g 4. A system according to claim 3 wherein the mechanism for controlling the operation of the rolls includes.

means providing for a second period of dwell of said rolls during the completion of formation of the cross seal.

5. A system for forming, filling, exhausting and sealing packages of flexible material comprising opposed sealing rolls between which opposed strips of packaging material are fed and formed into packages, said rolls having axially spaced opposed circular surfaces for forming edge seals for the packages and circumferentially spaced opposed cross members for forming cross seals for the packages, at least one cross member of a pair having a groove in a part of the surface thereof, a nozzle connected to a source of vacuum and adapted to project into said groove, driving mechanism for said rolls and mechanism for controlling the operation of said rolls and of the nozzle including a clutch for the driving mechanism and a timer controlling operation of said clutch to provide a period of dwell for the rolls when the cross seal members are opposed and thereafter cause said rolls to resume movement to complete formation of the cross seal, and means controlled by said timer to project said nozzle into the package in the region of said grooves and to withdraw it during said period of dwell, to evacuate the package.

6. A system for forming, filling, exhausting and sealing packages of flexible material comprising opposed sealing rolls between which opposed strips of packaging material are fed and formed into packages, said rolls having axially spaced opposed circular surfaces for forming edge seals for the packages and circumferentially spaced opposed cross members for forming cross seals for the packages, at least one cross member of a pair having a groove in a part of the surface thereof, a nozzle connected to a source of vacuum and adapted to project into said groove, driving mechanism for said rolls and mechanism for controlling the operation of said rolls and of the nozzle including a clutch for the driving mechanism and a timer controlling operation of said clutch to provide a period of dwell for the rolls when the cross seal members are opposed and thereafter cause said rolls to resume movement to complete formation of the cross seal, means controlled by said timer to project said nozzle into the package in the region of said grooves and to withdraw it therefrom during said period of dwell, a normally closed valve for said vacuum nozzle and means controlled by said timer to open said valve during said period of dwell.

7. A system according to claim 5 wherein the driving mechanism for the rolls includes means providing a second period of dwell for the rolls during completion of the cross seal.

8. A system according to claim 6 wherein the driving mechanism for the rolls includes means providing a second period of dwell for the rolls during completion of the cross seal.

9. A system for forming, filling, exhausting and sealing packages of flexible material comprising opposed sealing rolls between which opposed strips of packaging material are fed and formed into packages, said rolls having axially spaced opposed circular surfaces for forming edge seals for the packages and circumferentially spaced opposed cross members for forming cross seals for the packages each cross member of a pair having a groove in a part of the surface thereof opposed to a like groove in the opposed cross member, resilient inserts in said grooves, a nozzle connected to a source of vacuum and adapted to project into the package in the region of said grooves, driving means for the rolls and means operating to project said nozzle into the package in the region of said grooves and to withdraw it during theformation of the cross seals, the said resilient inserts press- 8 ing the strips together in the region of said grooves as the nozzle is withdrawn.

10. Asystem according to claim 9 wherein the driving mechanism for the rolls is controlled to provide a period of dwell for the the rolls when the grooves of a pair of cross seal members are opposed.

11. A system for forming, filling, exhausting and sealing packages of flexible material comprising opposed sealing rolls between which opposed strips of packaging material are fed and formed into packages, said rolls having axially spaced opposed circular surfaces for forming edge seals for the packages and circumferentially spaced opposed cross members for forming cross seals for the packages, at least one cross member of a pair having a groove in a part of the surface thereof, and resilient insert in said groove, a nozzle connected to a source of vacuum and adapted to project into the package in the region of said groove, driving mechanism for the rolls and means operating to project said nozzle into the package in the region of said groove and to withdraw it during formation of the cross seal, the said resilient insert pressing the strips together in the region of said groove as the nozzle is withdrawn.

12. A system according to claim 1 wherein the grooves have resilient inserts adapted to press the strips together as the nozzle is withdrawn.

13. A system according to claim 3 wherein the groove has a resilient insert adapted to press one of the strips against the other as the nozzle is withdrawn.

14. In a method of forming, filling and sealing sue-- cessive packages from opposed strips of packaging material and exhausting the package through a vacuum nozzle, the method which comprises passing said strips between opposed sealing rolls to form edge seals and a first end seal for a package, introducing the material to be packaged, forming a portion of the other end seal of the package leaving an unsealed passage of limited area therein in the region of said nozzle, exhausting the package through said passage by said nozzle and thereafter passing the said strips further between said rolls to close said passage and complete formation of said other end seal and to form a first end seal for the succeeding package.

15. In a method of forming, filling and sealing successive packages from opposed strips of packaging material and exhausting the package through a vacuum nozzle, the method which comprises passing said strips between opposed sealing rolls to form edge seals and a first end seal for a package, introducing the material to be packaged, forming a portion of the other end seal of the package leaving a passage of limited area therein in the region of said nozzle, exhausting the package through said passage by said nozzle, withdrawing said nozzle while continuing to apply suction, and thereafter passing the said strips further between said rolls to close said passage and complete formation of said other end seal and to form a first end seal for the succeeding package.

16. In a method of forming, filling and sealing successive packages from opposed strips of packaging material and exhausting the package through a vacuum nozzle, the method which comprises passing said strips between opposed sealing rolls to form edge seals and a first end seal for a package, introducing the material to be packaged, forming a portion of the other end seal of the package leaving a passage of limited area therein in the region of said nozzle, interrupting movement of said strips, exhausting the package through said passage by said nozzle while movement of the strips is interrupted and thereafter passing said strips further between said rolls to close said passage and complete the formation of the other end seal and to form a first end seal for the succeeding package.

17. In a method of forming, filling and sealing successive packages from opposed strips of packaging material and exhausting the package through a vacuum nozzle, the method which comprises passing said strips between opposed sealing rolls to form edge seals and a first end seal for a package, introducing the material to be packaged, forming a portion of the other end seal of the package leaving a passage of limited area therein in the region of said nozzle, interrupting movement of said strips and exhausting the package through said passage by said nozzle while movement of the strips is interrupted and thereafter withdrawing said nozzle from the package and passing said strips further between said rolls to close said passage and complete formation of said other end seal and to form a first end seal for the succeeding package.

18. In a method of forming, filling and sealing successive packages from opposed strips of packaging material and exhausting the package through a vacuum nozzle, the method which comprises passing said strips between opposed sealing rolls to form edge seals and a first end seal for a package, introducing the material to be packaged, forming a portion of the other end seal of the package leaving an unsealed passage of limited area therein in the region of said nozzle, exhausting the package through said passage by said nozzle and thereafter withdrawing said nozzle and pressing the strips together in the region of said passage as the nozzle is withdrawn, completing formation of the other end seal and forming a first end seal for the succeeding package.

19. In a method of forming, filling and sealing successive packages from opposed strips of packaging material and exhausting the package through a vacuum nozzle, the method which comprises passing said strips between opposed sealing rolls to form edge seals and a first end seal for a package, introducing the material to be packaged, forming a portion of the other end seal of the package leaving a passage of limited area therein in the region of said nozzle, exhausting the package through said passage by said nozzle, withdrawing said nozzle and pressing said strips together in the area of the passage While continuing to apply suction and thereafter passing the said strips further between said rolls to complete the closing of said passage and formation of the other end seal and to form a first end seal for the succeeding package.

20. In a method of forming, filling and sealing successive packa es from opposed strips of packaging material and exhausting the package through a vacuum nozzle, the method which comprises passing said stripsbetween opposed sealing rolls to form edge seals and a first end seal for a package, introducing the material to be packaged, forming a portion of the other end seal of the package leaving a passage of limited area therein in the region of said nozzle, interrupting movement of said strips, exhausting the package through said passage by said nozzle while movement of the strips is interrupted and thereafter withdrawing said nozzle and pressing the strips together in the region of said passage as the nozzle is withdrawn, completing formation of the other end seal and forming a first end seal for the succeeding package.

References Cited in the file of this patent UNITED STATES PATENTS 2,387,812 Sonneborn Oct. 30, 1945 2,468,517 Salfisberg Apr. 26, 1949 2,565,444 Waters Aug. 21, 1951 2,626,494 Lewis Jan. 27, 1953