Packaging apparatus

In plastic pouch forming, improved vacuum boxes that are movable toward and away from one another are provided. Each vacuum box comprises a series of superimposed, paired, mutually spaced vacuum ports in fluid communication with one another, the outer pair of ports being resilient and adapted to frictionally engage a wall portion of a flattened pouch and to flex open upon application of a vacuum to draw portions of the pouch wall into a cavity defined by an underlying port. In the specific and preferred embodiments of the invention, the vacuum boxes comprise (a) a vacuum chamber defined by a hollow metal box body and a cover plate comprising a pair of vacuum ports; (b) a resilient rubber pad affixed to the box cover plate comprising a pair of vertical, elongated vacuum ports, preferably in the form of slots and aligned with overlying the vacuum ports of the cover; and (c) a thin, high friction resilient facing affixed to the rubber pad comprising a pair of vertical, elongated vacuum ports, preferably in the form of slits, and overlying the vacuum slots, preferably in offset lateral relation thereto. A flattened, pouch is placed between the vacuum boxes and a vacuum is introduced to force the confronting flat surfaces of the pouch into frictional engagement with the facing material and to flex the slits formed therein thereby drawing portions of the pouch walls into the slits and partially into the cavity formed by the vacuum slots.

BACKGROUND OF THE INVENTION 
This invention relates to packaging apparatus, and more particularly to 
apparatus useful in forming pouches to facilitate insertion of articles 
therein. 
Devices are known in the food packaging art for opening thin plastic and/or 
plastic-foil bags to enable their filling at a station along a transport 
path of a carrier for such bags. The bags are generally supplied in the 
form of stacks of flattened bags which may be simple sacks or 
substantially rectangular plastic panels formed at their bottoms with 
gussets or a panel of substantially V-cross section so that the section of 
the bottom has a W-cross section. One system for opening such bags 
comprises vacuum means for spreading the lips of the mouth of the bag and 
a mechanical element which is introduced through the open end to spread 
apart the walls of the bag to the bottom. 
Difficulties are frequently encountered with such a system in that the 
vacuum is often insufficient to maintain the bag in opened position during 
insertion of the mechanical member at high speed and under high friction 
generating conditions causing the pouch to fall away from the ram. This 
has been a particular problem with pouches constructed from materials 
having high slip properties such as, for example, paraffin-coated or wax 
treated cellophane. 
The following is a listing of U.S. Patents believed material to the state 
of the art to which this invention pertains. 
No. 2,224,656 discloses opposed suction devices movable toward one another 
to engage a flattened bag and movable apart to open the bag. 
No. 2,281,516 discloses opposed suction boxes A for opening collapsed bags 
B in preparation for filling. 
No. 3,453,799 discloses pouch opening apparatus, including suction cups 54, 
each provided with a flat edge portion 54a for eliminating tendency of the 
pouch wall to become wrinkled. 
No. 4,033,096 discloses opposed pairs of suction cups 6 and 9 operative to 
engage and spread the walls of flattened pouch 1. 
No. 4,150,519 discloses a pair of opposed vacuum boxes that are movable 
toward and away from one another and comprising vacuum cups having an 
insert with a recessed face portion whereby a vacuum forces surfaces of a 
pouch placed between the vacuum boxes onto the vacuum cups and partially 
into the recessed portion thereof. 
It is an object of this invention to provide an improved apparatus of the 
foregoing type. 
It is another object of this invention to provide an improved vacuum 
apparatus which is particularly adapted to retain thin plastic-foil 
materials having high slip characteristics to ensure full opening of a 
pouch through insertion of a mandrel. 
These and other objects of the invention will be apparent from the 
description of the invention which follows. 
SUMMARY OF THE INVENTION 
In achievement of the above objectives, the invention contemplates in 
packaging apparatus, means for handling a flattened pouch having opposed 
planar walls joined along side portions thereof to define an opening for 
receiving material to be packed, the combination comprising: a pair of 
opposed vacuum box means mounted for movements toward and away from one 
another; improved means disposed on each said vacuum box means defining a 
series of superimposed, paired, mutually spaced vacuum ports of differing 
configuration and in fluid communication with one another, the outer pair 
of ports being resilient and adapted to frictionally engage a wall portion 
of the flattened pouch; means for moving said vacuum box means toward one 
another into position engaging the walls of a flattened pouch in the 
region of its opening; means for introducing a vacuum through said vacuum 
box means to effect flexing of said resilient outer port and to draw 
portions of said pouch walls through said outer port into a cavity defined 
by the underlying port to initiate formation of a crease in said pouch 
walls; means for moving said vacuum box means apart while maintaining said 
vacuum to urge said pouch walls apart; and means for shaping and moving 
the shaped pouch to a subsequent station. 
The manner in which the foregoing as well as other objectives and 
advantages of the invention may best be achieved will be more fully 
understood from a consideration of the following description, taken in 
light of the accompanying drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to FIGS. 1 to 3, there is seen pouch handling apparatus 10 
for opening and transforming a pouch 11 from flattened configuration (FIG. 
1) into rectangular configuration (FIGS. 2 and 3) for insertion into a 
carton 12 (FIG. 3), or other suitable means, for subsequent filling and 
sealing by conventional means. 
Pouch 11 is formed from a single rectangular sheet of flexible, plastic 
having high slip characteristics, such as paraffin coated cellophane 
material 13, folded onto itself so that it is W-shaped in vertical section 
and sealed along its edges, as seen at 14, to form an open-top container 
capable of being opened and transformed into generally rectangular cross 
section for filling. 
Handling apparatus 10 comprises means defining a pair of opposed vacuum box 
means 15 mounted on brackets 16 for movements toward and away from one 
another. Each vacuum box 15 is connected to a controlled vacuum source of 
known type, and shown diagramatically at V, FIG. 1, through tubes 17. 
As is best seen in FIG. 4, each vacuum box 15 includes a vacuum chamber 18 
comprising a hollow box body 19 and a box cover plate 20 having a pair of 
mutually spaced vacuum ports 21. A resilient, flexible pad 22, formed of 
closed cell silicone sponge rubber, neoprene rubber and the like, having a 
pair of elongated vacuum ports, preferably in the form of slots 23, is 
affixed to cover plate 20 by suitable means, for example, by a suitable 
adhesive or the like whereby the vacuum slots 23 are in substantial 
alignment and in fluid communication with the vacuum ports 21 of the cover 
plate. A thin resilient, flexible facing material, 24, suitably treated to 
have high surface friction characteristics and comprising a pair of 
elongated, vertical ports, preferably in the form of slits 25, is affixed 
to the flexible pad 22 whereby the vacuum slits 25 overlie and are 
superimposed over said vacuum slots 
The slits 25 are suitably dimensioned to be substantially narrower in width 
than the slots 23 and are preferably slightly offset laterally in relation 
to the slots 23 and ports 20. 
A forming mandrel 26 of rectangular configuration is mounted above vacuum 
box means 15 and is movable vertically by conventional means not shown, 
between the retracted position seen in FIGS. 1 and 2 and the partially 
extended position, seen in FIG. 3, and to a fully extended positioned, not 
shown but as described hereinbelow. 
In operation, a flattened pouch 11 to be opened and filled is moved between 
vacuum boxes 15 by known suitable apparatus, and the box means are then 
moved toward one another to clamp the pouch in the position shown. As best 
seen in FIGS. 2, 6 and 7, pouch 11 is engaged by the facing 24 to form a 
fluid and frictional seal against the walls of the pouch in the regions of 
the upper corners of the pouch. The high frictional characteristic of the 
facing material functions to frictionally retain the pouch material 
whereby the film substantially conforms to the large surface area of the 
facing material. A vacuum is applied to a box means 15 from source V 
through their respective tubes 17 causing the resilient material to expand 
or flex or otherwise flexibly yield to form an opening defined by lip 
portions 28 and 29 which remain in frictional engagement with the portions 
of the pouch material while other portions are drawn into the cavity 
defined by the underlying vacuum slot. Application of a vacuum has the 
effect of pulling the pouch material through the slit 25 and into the 
cavity defined by slot 23. As best seen in FIGS. 6 and 7, as a result of 
the positioning and relative sizing of the superimposed slit/slot/port 
arrangement, a tortuous cavity is formed into which a portion of the bag 
wall is drawn to form a bead 27. This action gives rise to a relatively 
tight grip on the pouch walls. Such action also creates four vertical 
creases in the pouch walls extending downwardly toward its bottom. 
With the pouch walls thus retained, the vacuum boxes are moved apart as in 
FIG. 2 and while thus positioned, rectangular shaping mandrel 26 is 
lowered for insertion into the pouch (FIG. 3) followed by movement to 
square the lower portion of the pouch. Continued downward movement of 
mandrel 26, accompanied by release of the vacuum on tubes 17 and box means 
15, removes the squared-up pouch from retention by the vacuum slit/slot 
cavity and inserts it into a suitably disposed rectangular carton 12 for 
movement to suitable filling apparatus. 
In the preferred and best mode of operating the invention, the vacuum box 
body 19 and cover plate 20 may be formed of any suitable rigid material 
and preferably will be constructed of metal; the flexible pad 22 will be a 
closed cell, rubbery material and most preferably will be silicone sponge 
rubber. The facing 24 will be a high friction surface resilient material 
and most preferably will be a polyurethane resin, treated to have high 
friction surface characteristics and available commercially as "ML6-55" 
from Meridian Laboratories, Middleton, WI. 
While the vacuum boxes have been described and illustrated herein as having 
a pair of mutually spaced vacuum port and slots positioned in alignment 
and a pair of vacuum slits offset over the slots, it will be understood 
that the invention contemplates such vacuum boxes with any numerical and 
spatial arrangement thereof as may accomplish the objectives of this 
invention, the most important consideration being the provision of at 
least two pairs of vacuum ports in fluid communication wherein the outer 
pair of ports is resilient and adapted to frictionally engage a wall 
portion of a flattened pouch and to flex or otherwise open upon 
application of a vacuum to draw portions of the pouch wall into an 
underlying cavity. It is contemplated that the grip exerted on the pouch 
may be varied by the relative thickness of the resilient facing and rubber 
pad as well as by the extent of alignment of the respective vacuum ports 
or both, assuming a constant vacuum. It is also contemplated that more 
than two vacuum slit/slot port paired combinations may be employed, if 
desired. Additionally, instead of the vacuum boxes with affixed pad and 
facing coextensive with the surface of the box cover plate, it is 
contemplated that suitable boxes may comprise a box body and face plate 
with resilient pad and facing and their respective slots and slits affixed 
only in the areas overlying the vacuum ports. Similarly, the boxes may be 
provided with suitable compartments whereby the various ports, slots and 
slits may be slidably mounted or inserted in desired positions to 
accomplish the objectives of the invention. Other modifications are 
contemplated as may fall within the scope of the appended claims.