POUCH FORMING MACHINE WITH VERTICAL JAW ADJUSTMENT MECHANISM

Abstract

An adjustment mechanism for the vertical jaws of a vertical form, fill, seal pouch machine includes a frame having a track for supporting a cross arm and a pair of drive wheels turning a cross rod which rotates a drive rod to move the support bar for the vertical jaws to and away from a forming tube of the machine. A similar mechanism moves a support device for a die cutter forming a hanger hole on the pouch to and away from the forming tube.

Description

FIELD OF THE INVENTION

The invention relates to a vertical form, fill, seal machine for flexible pouches. More particularly, the invention relates to an adjustment mechanism for the vertical jaws of the machine.

BACKGROUND OF THE INVENTION

Standup flexible pouches are also known as Doypacks. These pouches are formed of a flexible film on machines such as a vertical form, fill, and seal machine. The film may be a single layer of suitable plastic but more typically a laminate of plastics and/or foil. A sheet of film is pulled over a plow and around a forming tube, so that side edges of the sheet meet in front of the forming tube. Vertical heat seal bars seal the side edges together to form a sleeve. The vertical seal formed becomes the top of the pouch. A die cutter is used to form a hanging hole or euro hole in the vertical seal. A horizontal seal is placed across the sleeve to form a bottom edge seal. It is frequently necessary to adjust the distance between the vertical jaws and forming tube because of stretching or variance in the film. If the film has stretched, the seal bars will not place the seal inwardly from the edges resulting in an unacceptable package. In the past, this operation has required the machine to stop and the adjustment is made before restarting the machine.

SUMMARY OF THE INVENTION

Disclosed is an adjustment mechanism for vertical jaws of a pouch forming machine. The adjustment mechanism includes a drive rod and a cross rod mounted to a frame. The rods are rotated by a drive mechanism to move a support arm to and away from a forming tube. In the preferred embodiment the drive mechanism is a pair of hand wheels. The support arm carries a pair of vertical jaws which have heat seal bars to seal edges of a film together to form a sleeve of laminate material. The machine may include an adjustment mechanism for a die cutter which forms a hang hole in the vertical seal. The adjustment mechanism includes a second drive rod and a second cross rod which are rotated to drive a support arm for an adjustment mechanism for the hole cutter along the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a machine for forming flexible pouches according to the invention;

FIG. 2 is a partial perspective view of the machine showing a film in position around a formed tube;

FIG. 3 is a perspective view of the adjustment mechanism for the vertical jaws and for the die cutter taken from the rear;

FIG. 4 is a perspective view of the adjustment mechanisms for the vertical jaws and for the die cutter taken from the front;

FIG. 5 is a cross-sectional view of a cross bar, drive wheels, and drive rod taken along section lines 5-5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Shown in the drawings is a vertical form, fill, and seal pouch machine 10 which includes a novel adjustment mechanism 31 for easy and precise adjustment of vertical jaws which form a vertical seal during a pouch forming operation. The adjustment may be made while the machine is operating. The machine also includes an adjustment mechanism 100 for a die cutter for forming a hanger hole in the vertical seal. The machine may be used to form zipper pouches or standup pouches.

As shown in FIGS. 1 and 2, the vertical form, fill, and seal machine 10 includes a housing 12. A sheet of film 14 is fed into the machine 10 from a roll 16. As shown in FIG. 2, the film is fed through a series of rollers (not shown) to the machine wherein it is guided over a roller 18 and over a plow 20 and around a forming tube 22. The forming tube 22 extends vertically from a top of the machine towards a bottom. The forming tube 22 has a curved rear surface 24, front surface 26, and a pair of parallel sides 28. The film has a pair of side edges 30 which after leaving the plow are pulled together around the forming tube and positioned between a pair of seal bars 32 carried by vertical jaws 34. A heat unit 36 is mounted to the vertical jaws 34 to heat the film for sealing. Alternatively, the seal bars may have heating elements.

As shown in FIG. 3, a pneumatic actuator 98 moves the vertical jaws 34 and the seal bars 32 together to seal the side edges 30 together to form a sleeve 36 with a vertical seal 38. If a zipper 40 is added, the zipper is fed from a reel 42 over a roller 44 at the top of the machine 10 and down between the edges 30 of the film and the seal bars 32. It should be understood that the pouch 46 is formed sideways with the bottom of the pouch extending around the back of the forming tube and the vertical seal becomes the top of the pouch. Near the bottom of the machine horizontal jaws 48 move seal bars 50 to form a seal. Product is then filled from a fill tube 52 into the sleeve above the horizontal sleeve. The pouch is moved downwardly by a belt mechanism 54 and another horizontal seal is placed on the sleeve. The horizontal seal is severed through the middle by a cutter (not shown) and a sealed filled pouch drops to a conveyor 56 below.

The adjustment mechanism 31 for the vertical jaws 34 is best shown in FIGS. 3-4. The adjustment mechanism 31 for the vertical jaws includes a frame 60 supporting an upper pair of tracks 62. The frame 60 is mounted to one side of the housing 12. A support arm 66 extends perpendicularly from the frame 60. The support arm 66 has a carriage 63 with a pair of cars 68 which ride along the upper pair of tracks 62. The cars 68 have a smooth bearing-like surface such as Delrin. A drive mechanism moves the support arm to and away from the front of the forming tube to adjust for stretching in the film. The drive mechanism includes a first drive rod 70 which has a threaded portion 72 at one end. The threaded portion 72 is received in a nut 76 having internal threads mounted to the support bar. The other end 78 of the drive rod 70 is received into a box 80 mounted to the frame 60.

As best shown in FIG. 5, the box 80 has a bearing 82 in one side 84 to rotatably support the drive rod 70. A cross rod 86 passes through two other sides 88 of the box. A bevel gear 90 is mounted on the end of the drive rod 70 to engage a bevel gear 92 on the cross rod 86 to permit the cross rod 86 to rotate the drive rod 70. This in turn moves the support arm 66 by way of the nut 76 along the upper tracks 62. A pair of hand wheels 94, 96 are mounted to either end of the cross rod 86. One of the hand wheels 94 is on an interior portion 95 of the housing and the other hand wheel 96 is disposed such that it is on the exterior of the housing. Locking mandrels 98 are also provided on the wheel boxes such that the position of the jaws may be locked merely by moving a lever to squeeze a brake surface inwardly against the cross rod.

Thus, rotation of one of the hand wheels 94, 96 rotates the cross rod 86 to drive the drive rod 70 to adjust the support arm 66 and jaws 34 to and away from the forming tube 22. In this way the position of the vertical seal 38 can be precisely and easily changed when the film becomes stretched or distorted as it moves through the machine 10. The operator can adjust the position of the jaws 34 by moving the hand wheel 94 from the exterior of the housing without stopping the machine.

The adjustment device 100 for the hanger hole punch die cutter 58 is mounted to the second set of rails 64. A second support arm 99 carries a vertical adjustment mechanism 101 for the die cutter. Like the support arm 66 of vertical jaw adjustment mechanism 31, the support arm 99 has a carriage 103 with a pair of cars 102 to slide on the second set of rails 64. The drive rod 106 and cross rod 108 are provided as well as a second set of hand wheels 110, 112 to adjust the position of the support arm along a horizontal plane inwardly and outwardly with respect to the forming tube 28. A box 105 with bevel gears (not shown) is also provided. The vertical adjustment mechanism 101 includes an upper arm 114 and lower bar 116 which are connected by a pair of tubes 118. A support bar 120 has bores 122 which ride up and down along the tubes 118. A screw rod 124 is mounted between the tubes to pass through the support bar 120. The support bar 120 has a threaded nut 124 to receive the threads 126 of the screw rod 124. A hand wheel 128 is mounted to the top of the screw rod 124 to rotate the tube to adjust the position of the second support arm upwardly and downwardly. A brake mandrel 126 is positioned above the second support arm and a lever rotates to advance a brake surface against the drive rod to prevent rotation once the vertical height is established.

At the distal end of the support bar 120 is a pneumatically driven die cutter 58 or hole punch. The hole punch punches a hole in the vertical seam 38 of the sleeve 22 to act as a hanging hole 130 for the pouch 46 once it is formed (FIG. 1). Thus, the die cutter adjustment mechanism operates in a similar fashion to the vertical jaw adjustment mechanism to move the die cutter assembly inwardly and outwardly with respect to the forming tube along a horizontal axis to properly position the hanger hole.

As an alternative to the drive wheels, a servomotor may be mounted to the frame to turn the drive rods to make the adjustment. The servomotor may be controlled by a control box to drive the motor in one direction or the other to adjust the positions of the support arm.

Thus is disclosed a novel adjustment mechanism for the vertical jaws and hanger hole die punch to readily adjust these mechanisms.

It will be understood that variations of the disclosure are within the scope and spirit of the invention as defined by the appended claims.

Claims

1. A machine for forming a pouch, the machine comprising: a housing;a forming tube, the forming tube being generally horizontally aligned within the housing;a frame mounted to the housing;a first drive rod pivotally mounted to the frame, the first drive rod having a threaded portion;a first support bar movably mounted to the frame, the first support bar having a portion threadably engaging the threaded portion of the drive rod;a set of vertical jaws having seal bars mounted to the support bar;a device for rotating the first rod so as to move the first support bar and seal bar to and away from the forming tube.

2. The machine of claim 1 wherein the first support bar has a nut portion in engagement with the threaded portion of the first drive rod.

3. The machine of claim 1 wherein the device for rotating the drive rod is at least one rotating member connected to a first cross rod having a bevel gear in engagement with the first rod.

4. The machine of claim 3 wherein the at least one rotating member is a pair of wheels, one of the pair of wheels mounted to the shaft outside of the housing and the other wheel of the pair of wheels mounted to the shaft on the inside of the housing.

5. The machine of claim 1 further comprising a die cutter mounted to a second support bar, the second support bar slidably mounted to the frame.

6. The machine of claim 5 further comprising a vertical lift mechanism for moving the die cutter along a vertical axis.

7. The machine of claim 6 wherein the machine further comprises a second drive shaft for rotatably moving the second support arm.

8. The machine of claim 7 wherein the machine further comprises a second cross rod in engagement with the second drive rod to move the second support arm to and away from the forming tube.