US3030747A

US3030747A - Package evacuating and severing apparatus

Info

Publication number: US3030747A
Application number: US73118A
Authority: US
Inventors: Jr Benjamin Karpowicz
Original assignee: PAK RAPID Inc
Current assignee: PAK RAPID Inc
Priority date: 1960-12-01
Filing date: 1960-12-01
Publication date: 1962-04-24
Anticipated expiration: 1979-04-24

Description

April 2 1962 B. KARPOWICZ, JR 3,030,747

PACKAGE EVACUATING AND SEVERING APPARATUS Filed Dec. 1, 1960 5 Sheets-Sheet 1 INVENTOR flaw/9mm knRPow/cz J ATTORNEY5 April 24, 1 B. KARPOWICZ, JR 3,030,747

PACKAGE EVACUATING AND SEVERING APPARATUS Z INVENTOR BENJAMIN kmwo mas J1?- firmfzadnek,

ATTORN EY6 April 24, 19 B. KARPOWICZ, JR 3,030,747

PACKAGE EVACUATING AND SEVERING APPARATUS Filed Dec. 1, 1960 5 Sheets-Sheet 3 501-! Fan wA w INVENTOR Baum/1v KA RPOWIGZ Jle.

W PM

ATTORN EY$ April 4, 1962 B. KARPOWICZ, JR

PACKAGE EVACUATING AND SEVERING APPARATUS 5 Sheets-Sheet 4 Filed Dec. 1, 1960 lllllL \W INVENTOR Haw/mm! An/zPan lcz J BY WV Mao ATTORNEYS A ril 24, 1962 B. KARPOWICZ, JR

Filed Dec. 1, 1960 5 Sheets-Sheet 5 SOL'S PUMP CAM I03 NOZZLE DOWN a .P P 50% vac UM v$-|5 D 1/ vAc. SWITCH NOZZLE UP TD-j. Mg II. E 1| V NOZZLE SIGNAL usu'r L's-2 50m 1 F NOZZLE CLUTCH LATCH G V SOL-3 LOCK ARM BLADE F RWAR H 154 5 0L-4- 7 FORWARD euwe BLADE RETRACT Tgsr I TS-l BLADE SIGNAL LIGHT MUY'OR .sToP START SWTER M Ls-5 "I REAROF BLADE r 55 M 2 N l CAM D4- o cs p SOL2 CAM 05 (AM mm RELEASE INVENTOR BEA/JAM nv KA RPo w/cz dR ATTORNEYS 3,639,747 PACKAGE EVACUATING AND SEVERING AFFARATUS Benjamin Karpovvicz, in, Greland, Pa, assignor to Pak Rapid, Inc, West Consholrociren, Pan, a corporation of Pennsylvania Filed Dec. 1, 1960, Ser, No. 73,118 12 (Slain-1s. ill. 53-112) My invention relates to apparatus for forming, filling, evacuating, sealing and severing packages made from a continuous strip of flexible packaging material.

There are two principal reasons for evacuating the packages, first to prevent or minimize 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 into a smaller space than that required for unevacuated packages.

In packaging machine of the type with which the present invention is concerned, 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 for products which are deposited between the opposed strips during formation of the package. Apparatus of this general type is illustrated in my Patent No. 2,840,961 which also includes means for evacuating air from the packages.

The present invention is illustrated and described in connection with a machine such as disclosed in said patent in which sealing rolls having three evenly circumferentially spaced cross sealing surfaces are employed and in which three packages are completed in a complete revolution of the rolls, i.e., the machine goes through three package forming cycles in each complete revolution of the rolls. It is to be understood, however, that the invention is equally applicable to machines having one or more cross sealing surfaces.

The present invention includes, among other things, improvements such as the starting of each cycle of operation under control of the degree of evacuation of the package, cutting off the completed package at the cross seal while the rolls are in final cross seal position by means of a reciprocating rod and blade passing through the cross sealing members of the rolls, locking the rolls firmly against rotation during the cutting off operation, automatically stopping the machine when machine malfunctions occur, such as jamming of the cut-off blade with consequent failure of the blade to return to its normal retracted position, operation of the machine to provide any degree of evacuation my merely changing the setting of the vacuum switch, adjustability of the notched cam plate to change the circumferential spacing of the notches to agree with the circumferential spacing of the holes in the sealing roll R-i which may slightly vary because of inaccurate machining or due to roll expansion because of heating, and means to prevent machine stalling indefinitely due to faulty seals or torn packaging material.

The cut-ofi mechanism disclosed is especially useful whenthe products being packaged are of irregular shape and particularly so when the evacuation of the package draws the packaging material closely about the articles. In such cases when the cut-off is made after the seal is formed and the packages are hanging free below the sealing members, I have found that the cross seal is apt to be cooked with relation to the cutting mechanism and when severed, the ends of the packages are not square with the sides. In my improved arrangement this Ohjection is completely overcome for the strips are held firmly between the sealing members when the cutting 2 blades operates with the result that the cuts are always parallel and square with the side of the packages.

I have illustrated my invention in connection with the accompanying drawings, wherein- FIGURE 1 is a sectional elevational view taken approximately on the line l-1 of FIGURE 2;

FIGURE 2 is a vertical section taken approximately on the line 22 of FIGURE 1;

FIGURE 3 is a fragmentary cross section taken on the line 33 of FIGURE 1;

FIGURE 4 is a more or less diagrammatic view illustrating the sealing rolls in the stopped position in which evacuation of the package takes place;

FIGURE 5 is a fragmentary view illustrating the position of the clutch latch when the rolls are in the stepped position of FIGURE 4;

FIGURE 6 is a fragmentary view illustrating the position of the blade mechanism when the rolls are in the stopped position of FIGURE 4;

FIGURE 7 is a diagrammatic view illustrating the cam positions when the rolls are in the stopped position of FIGURE 4;

FIGURE 8 is a fragmentary sectional elevational view showing the position of the ramrod and blade at the end of the forward or slitting stroke;

FIGURE 9 is a plan view of FIGURE 8;

FIGURE 10 is a face view of the cam plate of the cam lock device;

FIGURE 11 is a side view of FIGURE 10; and

FIGURE 12 is a schematic wiring diagram.

The machine in general comprises a pair of crimping or sealing rolls or dies R and R1 to which opposed sheet of packaging material P are fed, supporting framework F, driving mechanism D for imparting intermittent rotation to the rolls R and R1, a vacuum nozzle N connected to a vacuum pump 8 by means of a flexible tube 9, and cutting or slitting mechanism S. The driving roll R-l drives the roll R by means of loosely meshing gears 7 and the roll R is a spring urged toward the roll R4 in a well known manner.

In FIGURES 1, 2 and 3, the parts of the machine are shown in the positions they assume when a cross seal is being completed and when the drive pawl 10, of the driving mechanism D, is ready to start its idle movement in a clockwise direction to pick up the next tooth 11 of the driving or ratchet disk 12.

The gear reduction unit 13 of the driving mechanism is driven by belt drive 14 and its output shaft is provided with a one revolution clutch 15 of well known form for imparting intermittent drive to the rolls R and R1. The drive mechanism includes

drive sprockets

16 and 17, FIGURE 1. A chain 26 drivingly connects sprocket 16 with a sprocket 21 of a cam shaft 22 carrying a plurality of cams to be described hereafter.

A chain 23 drivingly connects sprocket 17 with a sprocket 24- on a crank shaft 25 carrying a crank disk 2d having a crank pin 27 connected by link 28 to a rock lever at 30. The drive pawl It is pivoted at 31 to the other end of the rock lever 2?. p

it is pointed out that, as shown in FIGURE 2, the clutch latch solenoid SOL-l previously had been momentarily energized to release clutch spring loaded trip latch 35 from the clutch pin 36 thus causing rotation of the sprocket drive I7, 23, 24. The clutch trip, the crank disk and the pawl device are so co-related that when the one revolution clutch was stopped at the end of a revolution, as shown in FIGURE 4, the pawl and ratchet disk 12 stopped at a point 37 approximately 20 degrees short of the final driving position of the pawl in accordance with the disclosure in my Patent No. 2,840,961 above referred to, thus providing a first period of dwell for the sealing rolls. At that stop point in a cycle of operation the vacuum nozzle N is actuated to evacuate the package as will further appear.

Release of the clutch latch 35 causes the pawl first to move in a counterclockwise direction through 20 thus rotating the sealing rolls to the final cross sealing position shown in FIGURES 2 and 3. As the drive continues the pawl moves clockwise in idle stroke to pick up the next tooth 11 of the ratchet disk 12.

- During this idle stroke of the pawl, the second period of dwell, the sealing rolls remain stationary and are locked in such position by means of a cam lock device CL. While the rolls are so locked the slitting mechanism S operates in a manner fully described hereinafter. Also at this time the product to be packaged may be introduced for packaging in the next package to be formed through the chute 110 diagrammatically indicated in FIGURES l and 3, for example, in the manner disclosed in my Patent No. 2,840,961.

It is to be observed that the transverse seals which are formed by the sealing rolls RR1 are about twice the width of the edge seals of the packages and form the top seal for one package and the bottom seal for the succeeding package after the slitting mechanism has cut the strips of packaging material. It is also to be noted that the filling of the packages whether manually or automatically is effected while the package is sealed at the bottom end and open at the top.

The cam lock device CL comprises a cam plate 40 having three evenly circumferentially spaced notches 41, one for each of the three cross sealing surfaces 42 of the roll R1, 2 spring loaded arm 43 pivoted on the frame at 44, a cam lock roller 45 carried by the arm 43, a cam lock solenoid SOL-2 and a link 46 connecting the solenoid to the arm 43. With the solenoid SOL-2 de-energized the lock roller 45 is firmly seated in the registering notch 41 of the cam plate 49. Thus the roll R-l is positively indexed and held locked in its indexed position until the lock roller 45 is solenoid released.

Referring now to the slitting mechanism S it will be seen that it comprises a reciprocating ram rod 50 having a slitting blade 51 secured thereto at one end, which, when in the retracted position shown in FIGURE 1 is clear of the adjacent face 52 of the roll R4. The rod 56 is mounted adjacent its blade end for sliding movement in a bearing block 53 secured to the frame member 54. Adjacent its other end the rod 50 has a bearing block 55 secured thereto, which block carries an antifriction bearing 56 slidable on a fixed parallel bar 57 spaced above the ramrod 50.

Reciprocatory movement is imparted to the ramrod 50 by means of a piston and cylinder device 60, the piston rod 61 of which is connected by a link 62 to a rock arm 63. The rock arm has telescopic connection 64 with the sliding block 55.

The piston and cylinder device 60 is provided with a fluid control valve 65 of a well known type adapted to control the back and forth reciprocation of the slitting blade. The valve is actuated for forward or cut-ofi movement of the blade by a solenoid SOL-3 which operates the valve to admit fluid under pressure to the right hand end of cylinder 60 and for rearward or retract movement of the blade by a solenoid SOL-4, which operates the valve to admit fluid under pressure to the left hand end of cylinder 60.

As clearly seen in FIGURE 3 the sealing roll R-l is provided with a longitudinally extending hole 70 parallel to the axis of the roll and extending through the roll from end to end, there being one such hole located centrally of each of the three cross sealing surfaces 42 and spaced inwardly therefrom. Each hole 70 has a longitudinal slot 71 extending radially outwardly from the hole to the sealing surface 42 to accommodate the blade 51.

The holes 70 are so located in the roll with respect to the location of the ramrod 50 that when the rolls are in locked sealing position, as shown in FIGURES l and 3,

a hole 70 is in aligned registry with the ramrod 50. Thus, when the ramrod and blade move in forward stroke, i.e., from right to left as viewed in FIGURE 1, they pass through the aligned hole 70 and slot 71 to slit or cut off the package which has been formed and sealed, it being noted that the sealing surfaces 42a of the mating roll R are provided with registering longitudinal clearance slots 72 for the blade. It will be observed that the slit occurs at the middle of the area sealed by the sealing surfaces of the rolls thus forming a final end seal for completed package and a first end seal for the succeeding package of substantially equal size.

Particular attention is called to the fact that when the slitting operation takes place the sealing roll R-1 is positively locked, by the cam lock device CL, against rotation and in accurate index with the ramrod and blade. This not only ensures that the rod will enter the hole without displacement, but also ensures against binding of the rod and blade in the hole 70 thus preventing any strains on the ramrod or other parts of the machine such as would result if rotational movement of the roll could take place at a time when the rod is in the roll when it would act in the nature of a dowel.

It is pointed out that although the blade has a long stroke, particularly when slitting wide packages, the piston of the cylinder device 60 has a relatively short stroke because of the relation of the point of connection of the link 62 to the pivot point of the rock arm 63, thus enabling the overall size of the machine to be kept down.

The parallel mounting of the reciprocating ramrod and blade and the passing of the rod and blade through an accurately positioned hole in the locked roll which is parallel to the rod, together with the fact the other package material is firmly gripped between the rolls at the time of cutting ensures of a clean accurate cut at right angles to the sides of the package.

The rolls R and R1 have cut out portions or grooves at the

cross seal suffaces

42, 42a, FIGURES 3 and 4, for accommodating the vacuum nozzle N when the rolls are in the evacuating position as shown in FIGURE 4. When the rolls are in this position the nozzle N is lowered by means of a piston and cylinder device 81 having a fluid control valve 82 of well known type (similar to the piston and cylinder device 60 and valve 65) to control the up and down movement of the nozzle. The valve 82 is actuated to its position to effect downward movement of the nozzle by a solenoid SOL-5 and to its position to effect upward movement of the nozzle by a solenoid SOL-6.

Reverting now to the cam lock device CL it is pointed out that the cam plate 40, FIGURES l0 and 11, is formed of three sections 85, each of which carries one of the notches 41 above referred to. These sections are adjustably secured to a flange member 86 secured on the shaft of the roll R-l by means of screws 87 and slots 88. This adjustment enables the circumferential spacing of the notches 41 to be altered to correspond to the circumferential spacing of the holes 70 in the roll R-l. Thus, if due, for example, to inaccurate machining, the holes 70 in the roll R-l are not evenly spaced circumferentially, the circumferential spacing of the notches 41 of the cam plate 40 can be adjusted to agree with the circumferential spacing of the holes of the roll thus ensuring that, with each index of the rolls, the ramrod will be in coaxial alignment with the hole in the roll.

Also, since the rolls are heated by means of heaters 89 a certain amount of expansion of the rolls takes place which has a tendency to slightly alter the spacing of the holes 70 and because of this when setting up a machine for operation the rolls are preferably allowed to heat up to their running temperature and then the cam plate is adjusted to have the spacing of the notches agree with the spacing of the holes in the roll.

the nozzle N to its up position.

Sequence of Operation The sequence of operation will now be described with particular reference to FIGURES 4-7 and to the sche- Imatic wiring diagram of FIGURE 9.

In FIGURES 4-7 the various units of the machine are shown in the positions they assume at the start of a cycle, i.e., the rolls R, R1 are in their first stop position in which the drive pawl and ratchet disk 12 areat their stop point 37, the clutch latch 35 is engaged by the clutch pin 36 and has stopped the one revolution clutch at the end of a revolution, the cam lock 43 and roller 45 are retracted from notch 41 of the cam plate 44 the vacuum nozzle N is in its down or package evacuating position and the blade ramrod is in its retracted or rearward position.

It will be observed that with the various units in the positions just described, the lug member lull carried by the nozzle N and secured to the piston rod 83 of the piston and cylinder device 31, has moved downward away from the upper limit switch LS-Z to open it, the rod 101 carried by the cam lock arm 43 is out of contact with the limit switch LS-3 so that this switch is open,- the lug member 102 carried by the piston rod 61 of the blade actuating piston and cylinder device at FIGURE 4, is out of contact with the forward limit switch LS-4 of the slitting mechanism S so that this switch is open, the rear end of the ramrod 50 has closed rearward limit switch LS-h', cam 103 has momentarily closed cam switch CS-l, cam Hi l has opened cam switch 306, cam 135 has opened cam switch (15-7 and vacuum switch VS-15 (FIGURE 4) in the vacuum line 9 of the vacuum pump 8 is open, but will close when the degree of the vacuum in the package has reached a predetermined number of inches.

The vacuum switch VS-IS is of the well known Bourdon tube type and is so set that when the degree of vacuum in the package reaches a predetermined amount, the Bourdon tube will close a mercury switch in well known manner.

In setting up the machine for automatic operation, panel control switch PS-l (line B, FIGURE 12) is set to pump on position and test switch TS-l (line I) is set to on position.

When the start button switch SS (line M) is depressed, automatic motor starter coil MS (line M) is energized and locked in through holding contacts 106 (line N) and from then on the machine will operate automatically until a machine malfunction occurs or until the stop switch lit? (line M) is pressed.

The first'switch to operate is cam switch CS-l (line B). This switch is momentarily closed by cam 103, FIGURE 7 and this de-energizes a time delay relay TDR (line A) setting up a time delay cycle and at the same time momentarily energizing solenoid SOL-5 (line B) to move the nozzle N to down position so as to evacuate air from the package.

When the degree of vacuum has reached a predetermined amount, vacuum switch VS-iS (line D) closes and energizes solenoid SOL-6 (line D) so as to move When the switch IS-15 closes, nozzle signal light 108 (line B) lights up. In normal operation this light lights up momentarily once in each cycle of the machine. However, if the light stays on it is a warning that either the vacuum tube is pinched orclogged or the air cylinder failed to raise the nozzle to its up position.

After the nozzle reaches its up position, limit switch LS-2 (line F) closes and energizes solenoid SOL-1 (line F) to release the clutch latch 35 of the one revolution clutch 15. Release of the latch 35 starts the driving mechanism D in operation thus first moving the pawl 10 in a counterclockwise direction to rotate the rolls through As the rolls approach the end of this 20 rotation, the cam lock roller 45 drops into the approaching notch package at the'cross seal.

4d of the cam plate 40 and at the end of the 20 rotation the roller firmly seats in the notch to lock the rolls R, R-l in cross sealing position with a hole 70 in accurate indexed alignment with the ramrod 50 and blade 51.

When the cam lock roller 45 seats in the notch 41 the rod Hill of the lock arm 43 closes limit switch LS-3 (line G and FIGURE 2) to energize solenoid SOL-3 (line G) of valve of the blade actuating piston and cylinder device 6t) so as to move the ramrod and blade in forward stroke through the registering hole of the roll R-l thus slitting the package material and severing the completed At the initiation of this forward stroke limit switch LS-5 opens.

When the ramrod reaches its full forward or slitting stroke the lug Hi2 carried by the piston rod 61 closes limit switch LS4 (line H). This switch energizes solenoid valve SGL t (line H) of valve d5 to move the ramrod in retract or return stroke. At the end of the return stroke the ramrod closes limit switch LS5 (line M).

The next switch to operate is cam switch 6 (line N and FIGURE 7) which may be termed as a circuit test switch. Limit switch LS5 (line M) and cam switch 5 (line N) are wired'in parallel and in the event that the blade ramrod should become jammed, preventing it from returning to its full retracted position, limit switch LS-S will not be engaged and therefore remains open. This switch in its open position closes the circuit for the blade malfunction signal light 105' (line K) thus giving a visual warning that the cut-off blade is forward. The signal light res flickers on and oil during normal operation of the machine. However, it will remain in the on position as long as the blade ramrod is jammed or if his left at cut-oil position during manual operation or testing procedure. If the machine shuts itself ofi and the light 109 remains on, the blade ramrod has become jammed and should be un-jarnmed manually.

However, if the ramrod does return to its full retracted position limit switch LS-5 (line M) closes and when cam test switch (ZS-6 (line N) is momentarily opened, the machine will continue to operate because rear limit switch LS-S was closed by the ramrod.

The next switch to operate is the cam switch CS-7 (line 0) of cam MP5, FIGURE 7 and when this switch is momentarily closed, solenoid SOL-2 (line 0 and FIG- URE 2) is energized to release the cam lock arm 43 and roller 45. By this time the drive pawl 10 has completed its idle stroke in a clockwise direction and has engaged the next tooth it of ratchet disc 12 and when the pawl starts in its drive-stroke in a counterclockwise direction, rotative movement is imparted to the rolls R and R4 because the lock roller 45 has been released.

The rolls continue to rotate and as they approach the first stop position as shown in FIGURE 4 the cam 103 momentarily closes cam switch CS-1 (line B) to propel the nozzle N to its down position and the cycle described above is repeated.

In connection with the cam switch CSll (line B) and vacuum switch VS-15 (line D) it is pointed'out that they are always closed before limit switch LS2 (line F) closes. However, due to a machine malfunction, vacuum switch VS-llS may fail to close and when this happens relay contacts TD-l (line B) of the time delay relay TDR which are wired in parallel with vacuum switch VS15 will close after the timer times out and machine operation is rescued.

The time delay relay is a well known pneumatically operated device and its timing mechanism is setto allow additional time than normal cycle time. In the absence of the machine rescue arrangement just described, it will be observed that if the vacuum switch V845 should remain open due to faulty seals in the package or torn packaging material, the machine would remain stalled for an indefinite period.

The timing cycle is cancelled out with each machine cycle and the above circuit does not function when acceptable packages are produced in the machine.

Control of the start of the cycle by means of the vacuum switch V-15 is advantageous for the reason that the degree of vacuum varies with the packaging of different articles. The employment of a vacuum controlled switch adapted to be set to close its switch contacts in accordance with the number of inches of vacuum produced in the package enables the air to be evacuated to the degree required for the particular article being packaged before the cycle of operation starts. In this connection it is pointed out that by merely adjusting the vacuum switch V-l the demands of various users as to the degree of air evacuation required can readily be met.

The means and method for evacuating the packages is quite similar to that disclosed in my Patent No. 2,840,961 the principal difference being that in the patented structure the length of time during which the package is being evacuated is under the control of a timer relay, whereas in the present application the period of evacuation is controlled by the switch V-IS which may be easily set to provide the degree of evacuation desired.

In any case, air evacuation is employed to a degree that will enable collapsing of the package material around the article to reduce the bulk of the package, this being particularly advantageous in keeping down the size of a box or container when a number of packages are to be placed in a box to meet sale or shipping requirements.

If it is desired to test the seal quality of packages made by the machine, the test switch TS-l (line I) is moved to its test position thus making dormant all the circuits from line A to line I. This allows the machine to operate and produce packages without actuating the cut-off or vacuum control circuits above described.

Although I have illustrated and described my invention in connection with the machine in which the heat sealing members are in the form of rolls and in which the packages may be evacuated, it will be understood that the method of slitting and the slitting mechanism can be used in packaging machines where the heat sealing members are of different form (reciprocating, for example) and in which no apparatus for evacuation for the packages is provided. The slitting feature alone is a great improvement over conventional methods and apparatus for severing individual packages from strips of packaging material, for the slitting blade will slit the packaging material at absolute right angles to the sides thereof, and will effect a neat clean even cut-off which many conventional methods fail to provide.

It will also be understood that when reference is made herein to opposed strips of packaging material, I also contemplate the use of a single strip of material which may be folded or formed into a tube with a single longitudinal seam.

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

It will also be understood that my invention will be applicable to and advantageous in machines where the packages are not evacuated.

I claim:

1. Package severing mechanism for automatic package forming and filling machines wherein the packages are formed from continuous opposed strips of packaging material, comprising opposed sealing members between which the strips are pressed to form transverse seals between packages, driving means to bring said sealing members into and out of sealing position, transverse opposed slots in the sealing surfaces of said sealing members, a

' knife for severing said strips of material between packages when said members are in sealing position, and means mounting said knife for reciprocating movement in said slots in a direction from one edge of the strip material to the other edge thereof.

2. An apparatus according to claim 1 wherein the driving means provides a period of dwell for the sealing members when the material is being severed.

3. Package severing mechanism for automatic package forming and filling machines wherein the packages are formed from continuous opposed strips of packaging material, comprising opposed sealing rolls between which the opposed strips are fed, said rolls having circumferentially spaced opposed cross members for forming cross seals for the packages, each cross member of a pair having an axially extending slot in the surface thereof opposed to a like slot in the opposed cross member, driving mechanism for the rolls providing a period of dwell for the rolls when the cross members are in sealing position, a knife severing said strips of material between packages when said members are in sealing position, and means mounting said knife for reciprocating movement in said slots in a direction fromone edge of the strip material to the other edge thereof when the cross members are in opposed sealing position during said period of dwell.

4. An apparatus according to claim 3 having means to lock the sealing rolls in position during the period of dwell.

5. An apparatus according to claim 3 having means to lock the sealing rolls in position during said period of dwell and means associated with the knife reciprocating mechanism to maintain the sealing rolls in locked position until the knife is fully withdrawn from the slots.

6. An apparatus according to claim 3 having means to lock the sealing rolls in position during the period of dwell comprising a notched cam plate having a plurality of notches, a cam lock adapted to engage said notches to lock the rolls in position and means to adjust the relative position of the notches.

7. Package severing mechanism for automatic package forming and filling machines wherein the packages are formed from continuous opposed strips of packaging material, comprising opposed sealing rolls between which the opposed strips are fed, said rolls having circumferentially spaced opposed cross members for forming cross seals for the packages, one cross member of a pair having an axially extending hole connected to the sealing surface by a slot, a like slot in the opposed cross member, driving mechanism providing a period of dwell for the rolls when the cross members are in opposed sealing position, a knife carried by a rod mounted to traverse lengthwise of the hole with the blade of the knife extending into said slots and means to reciprocate said rod in the hole when the cross members are in opposed sealing position whereby said blade will cut the opposed strips into individual packages during said period of dwell.

8. Package severing mechanism for automatic package forming and filling machines wherein the packages are formed from continuous opposed strips of packaging material, comprising opposed sealing rolls between which the opposed strips are fed, said rolls having circumferentially spaced opposed cross members for forming cross seals for the packages, one cross member of a pair having an axially extending hole connected to the sealing surface by a slot, a like slot in the opposed cross member, a knife carried by a rod mounted to traverse lengthwise of the hole with the blade of the knife extending into said slots and means to reciprocate said rod in the hole when the cross members are in opposed sealing position whereby said blade will cut the opposed strips into individual packages.

9. Automatic package forming apparatus for making packages from opposed strips of packaging material comprising opposed sealing rolls between which the strips of packaging material are passed, said rolls having circumferentially spaced opposed cross members for forming transverse seals for the packages each cross member of a pair having grooves in a part of the surface thereof opposed to like grooves in the opposed cross member and having a slot in the surface thereof opposed to a like slot in the opposed cross member, a nozzle connected to a source of vacuum and adapted to project into said grooves and a knife mounted to traverse lengthwise of the grooves, driving mechanism for operation of the rolls, the nozzle and the knife, the driving mechanism including means providing a period of dwell for the rolls when the grooves of a pair of cross seal members are opposed, thereafter providing another period of dwell when the slots of a pair of cross seal members are opposed, means operating to project said nozzle into the package in the region of the grooves and withdraw it during the first period of dwell to evacuate the package and means operating to project said knife into the slots and withdraw it during said second period of dwell to sever the package from the continuous strips.

10. Apparatus according to claim 9 wherein the oper- 1Q ation of the vacuum nozzle is controlled by adjustable means to regulate the degree of evacuation of the package.

11. Apparatus according to claim 9 wherein the operation of the vacuum nozzle is controlled by adjustable means to regulate the period of evacuation of the package and the first period of dwell of the sealing rolls.

12. Apparatus according to claim 9 having means to lock the sealing rolls in position during the second period of dwell and means associated with the knife reciprocating mechanism to maintain the sealing rolls in locked position until the knife is fully withdrawn from the slots.

References Cited in the file of this patent UNITED STATES PATENTS 2,265,253 Smith Dec. 9, 1941 2,730,852 Clark Jan. 17, 1956 2,803,100 Aalseth Aug. 20, 1957 2,840,961 Karpowicz July 1, 1958 2,902,802 Stirn Sept. 8, 1959