US3430844A - Valved bag end construction - Google Patents

Description

March 4, 1969 A. DANIELS VALVED BAG END CONSTRUCTION Sheet of5 Filed NOV. 8, 1967 INVENTOR ALLEN was ATTORNEY March 4, 1969 A. DANIELS 3,430,344

VALVED BAG END CONSTRUCTION Filed Nov. 8, 1967 Sheet 2 of s FIG.3

INVENTOR ALLE N DA Ni ELS BY g g AT TORNEY VALVED BAG END CONSTRUCTION Filed Nov. 8. 1967 FIG.4

mmvron ALLEN DANIELS United States Patent 3,430,844 VALVED BAG END CONSTRUCTION Allen Daniels, Shaker Heights, Ohio, assignor to Chase Bag Company, a corporation of Delaware Filed Nov. 8, 1967, Ser. No. 681,407 U.S. Cl. 229-625 4 Claims Int. Cl. 865d 31/14, 33/00 ABSTRACT OF THE DISCLOSURE A flattened tube of foldable and heat sealable material from which a rectangular shaped bag is formed with the flattened tube having rectangular end flaps projecting from both ends but on opposite sides of the tube and the end flaps being folded below the base of a rectangle when the ends of the tube are opened and folded. A valve sleeve blank is inserted in a corner of the bag between the end flap and a folded portion of the end of the flattened tube.

The present invention relates to a valved bag of heat sealable and foldable material having a rectangular shape when filled, more particularly, to the cutting, folding, and sealing of the ends of a flattened tube to provide a highstrength end construction.

For the packaging of many different materials, bags having generally the shape of a parallelepiped and with square ends have been used. Such shaped bags have numerous advantages over the prior known pillow-shaped bag including a more economical use of material and easier stacking of the filled bag. While such bags have been formed in a variety of different ways, a commonly used process utilizes a flattened tube of heat sealable and foldable material. The ends of the tube are suitably cut and subsequently folded to form square ends for the filled bag. Difliculties have been encountered in forming such a square end from a flattened tube wherein the end construction will be strong and leak-proof and where the bottom or end panel of the bag will be relatively flat to permit printing thereon. At the same time, at one corner of the bag there is generally provided a valve sleeve which facilitates the filling of the bag. In addition to the foregoing desired characteristics of such a bag there should be a minimum number of cuts and seals in the fabrication of the bag.

It is therefore the principal object of the present in vention to provide a novel and improved valved bag which is substantially rectangular in shape when filled.

It is another object of the present invention to provide a considerably stronger end construction for a rectangular shaped bag formed from a flattened tube.

It is a further object of the present invention to provide a valved bag of rectangular shape with an uninterrupted surface on the ends to permit printing thereon.

The foregoing disadvantages are eliminated and the above objects are achieved by the flattened bag having a rectangular shape when filled constructed in accordance with the present invention. In one aspect of the present invention, there may be provided a flattened tube of a heat scalable and foldable material with a rectangular end flap extending from each end of the flattened tube on opposite sides thereof. The end fiap has a width less than the width of the bag when the "bag is filled. A first fold line is provided below the base of each rectangular end flap. A second set of fold lines are provided in each side of the flattened tube extending at an angle of 45 degrees to the longitudinal axis of the tube from both Patented Mar. 4, 1969 ends of each first fold line to the edges of the flattened tube. A third set of fold lines are provided in each side of the flattened tube opposed from the second set of fold lines so that the second and third set of fold lines are in superimposed relationship in the flattened tube. There is a fourth fold line adjacent each end of the tube in the same side thereof from which the rectangular end flap extends. Each of the fourth fold lines extend transversely across the respective tube sides to the point of intersection of the second fold line with the edges of the flattened tube. Lines of heat sealing are provided along at least two of the edges of the end flap resulting from opening one end of the flattened tube and subsequently folding along the first, second, third and fourth fold lines. Folding of the second and third fold lines forms a rectangle and a rectangularly shaped inwardly extending valve flap is mounted in one corner of the bag between the above-described integral end flap and the formed rectangle. The valve flap extends inwardly beyond the inner edge of the formed rectangle so as to define a tubular "valve sleeve when the first fold is folded. The resulting valve sleeve facilitates the filling of the bag with material and enables the material to be retained within the bag after the bag has been filled.

Other objects and advantages of the present invention will be apparent upon reference to the accompanying description when taken in conjunction with the following drawings, wherein;

FIGURE 1 is a plan view of a portion of a continuous length of a flattened tubular material showing the cuts and folds therein for the bag of the present invention;

FIGURE 2 is a perspective view of an unfolded bag according to the present invention but slightly opened from its flattened condition;

FIGURE 3 is a plan view of the valve end of the bag but with the end flap unfolded;

FIGURE 4 is a side view of the bag with rectangular end flap opened;

FIGURE 5 is a plan view of completed bag in the flattened condition but with the end flap folded; and

FIGURE 6 is a perspective view of the bag end illustrated in FIGURE 5 but with the bag in the filled condition.

Proceeding next to the drawings wherein like reference symbols indicate the same parts throughout the various views a specific embodiment of the present invention will be described in detail.

With particular reference to FIGURE 1, there is illustrated at 10 a flattened tube of heat sealable thermoplastic material which is also foldable. This tube is a continuous length as it comes from the extruding or printing operation. While the embodiment of this invention is described as being formed from such a flattened tube of heat sealable material, it must be borne in mind that the present bag construction can also be formed from sheets which are folded over to form a tubular shape and then taped or otherwise sealed. Further, the sealing of the bag may be by tape or other sealing means differing from a heat sealing process.

The flattened tube 10 has longitudinal edges 11 and 12 and a central longitudinal axis 13. FIGURE 1 illustrates the manner in which a continuous tube is cut to form a single bag. In FIGURE 2, there is illustrated at 14 an individual bag in a somewhat flattened condition formed from the tube of FIGURE 1.

The flattened bag has two sides or faces with the front side being indicated at 15 and the rear side at 16 and shown in FIGURE 2. The ends 17 of the flattened bag 14 are formed by transverse cuts 18 as may be seen in FIGURE 1. The transverse cuts 18 are made in both sides of the flattened bag.

Longitudinal cuts 19 are then made in both sides of the bag and a further transverse cut 20 made in only the front side of the flattened bag. A further transverse cut 22 is made in the back side only of the flattened tubular member. As a result of these cuts in the end of the flattened bag, rectangular end flaps 21 and 21A are formed which extend from each side of the flattened tube but on opposite sides thereof as may be seen in FIGURE 2.

As will be subsequently apparent, the width of end flaps 21 is less than the width of the bag when the bag is filled.

The ends of the filled bag will be formed by the end flaps 21 and 21A which will provide an uninterrupted surface for printing on the ends of the bag. In order to obtain an end construction of considerable strength, each of the rectangular end flaps is folded along a first fold line 23 which is spaced below the base of the respective rectangular which base is indicated at 24. As shown in FIG- URES 1, 5 and 6, the fold line 23 extends below the ends of the base 24 to the fold lines 39 forming longitudinal edges of the bag when filled. A second set of folds 25 are provided in each side of the flattened tube and extend at an angle of 45 degrees to the axis 13 of the flattened tube to intersect the longitudinal edges 11 and 12 thereof.

Third fold lines 26 are provided in each side of the flattened tube but opposed from the second set of fold lines 25 so that the fold lines 25 and 26 at one end of the flattened tube will be in superimposed position as will be evident from FIGURE 2.

A fourth fold line 27 is provided at each end of the flattened tube but only on the same side from which the respective rectangular end flap 21 extends. The fourth fold line 27 extends transversely across the flattened tube to the points of intersection of the second fold lines 25 with the longitudinal edges 11 and 12 of the flattened tube. 4

In the assembly of the flattened bag as described above, the end of the flattened tube is slightly opened and folded along the fold lines 25, 26 and 27 to form the open bag end as illustrated in FIGURE 3. In order to form the valve sleeve in a corner of the bag, a rectangular valve flap 28 of a thin flexible material is inserted between the end flap 21 and the rectangle 29 resulting from the folds 25, 26 and 27 and extending to the end of flap 21. The valve flap may be held in place by tacking seals 30 at both ends of the valve flap and a full seal 31 made when the bag is open as shown in FIGURE 3. Seal 31 may be extended as shown at 31A in FIGURE 3. Seal 31 may made to fold at 23 without inserting a backing plate under flap 28 and rectangle 29. Any opening between the flap 28 and rectangle 29 beyond fold 23 will be to the inside of the bag. Seal 31 may terminate at a cross seal 31B short of fold 23 as shown in FIGURE 3 to provide an air escape channel and to insure no seal to the face of the bag.

The end flap 21 is then folded along fold line 23 to the position as illustrated in FIGURE 5. It is noted that by folding the end flap 21 along a line below the base of the rectangle, there is an overlapping of material at 32 at both ends of the end flap. Along the longer edge of end flap 21 and end seal 33 is made and along a shorter edge of the end flap a seal 34 is made. The seal 34 is between the end flap and the underlying rectangular portion 29. Additional seals may be made at 35 as shown in FIGURE 5.

As a result of this construction, the tubular valve sleeve will extend into the interior of the bag at 36 and the valve opening will be at 37. The cut ends of the flattened tubular member and the valve extension will all be inside of the bag as illustrated at 38.

When the bag is filled, the end flap 21 will be less in width than the width of the bag since the folds defining the filled bag will be at 39 as shown in FIGURES 5 and 6. Further, the entire end surface of the end of the bag as defined by the end flap 21 is uninterrupted so as to permit printing on the ends of the bag without any interference from heat or other seals and without sacrificing other objectives of his construction.

While the present invention has been described as employing one particular type of valve sleeve, it should be borne in mind that other desired valve sheet insertions or extensions may readily be incorporated in this bag construction.

While the present embodiment has been described as being made from a heat scalable thermoplastic material, the present construction may also be incorporated in paper bags with the seals made by tape, glue or any other suitable adhesive material. Further, the material may be multi-ply and the bag construction is not limited to the single-ply material as illustrated and described above. The term heat sealing has been employed generically and should be given a broad interpretation as is known in the art to cover constructions where the lines of heat sealing may be made either by a conventional heat sealing treatment, by high frequency heat sealing, by ultrasonic sealing or any other suitable heating arrangement.

Thus it can be seen that the present invention provides a considerably strengthened yet simplified end construction for a valved bag which is substantially rectangular when filled but formed from a flattened tube. The fold for the end flap is made at a point some distance below the base of the rectangular flap so as to eliminate the inherently weak junction where the end of a cut is in the corner. As a result of the presently described construction, there is formed a leak-proof corner having a double thickness of material but the necessity for providing separate pieces of gusset material is avoided.

What is claimed is:

1. A flattened bag having a rectangular shape when filled and comprising a flattened tube of scalable and foldable material and an integral rectangular end flap extending from each end thereof on opposite sides of the flattened tube, said end flap having a width less than the width of the bag when the bag is filled, a first fold line spaced below the base of each rectangular flap and extending beyond the ends of said base to lines forming longitudinal edges of the bag when filled, a second set of fold lines in each side of the flattened tube extending at an angle of 45 degrees to the axis of the tube from both ends of each first fold line to the edges of the flattened tube, a third set of fold lines in each side of the flattened tube opposed from said second set of fold lines and being superposed therewith, a fourth fold line adjacent each end of the tube in the same side from which the rectangular end flap extends, each of said fourth fold lines extending transversely across the tube side to the points of intersection of said second and third fold lines with the edges of the flattened tube, said tube being folded along said second, third and fourth fold lines and said flaps being folded along said first fold lines to provide bag ends having a double thickness of material at the folded corners, and lines of sealing along at least two of the edges of the end flaps.

2. A flattened bag as claimed in claim 1, and further comprising a flat, rectangular, inwardly extending valve flap of flexible material in one corner of the bag between one of said end flaps and the rectangle formed by opening the end of the bag and folding along the second and third fold lines, said valve flap extending inwardly beyond the inner edge of the said rectangle and from the side edge of said rectangle at the end of the bag to the end of said end flap thereby to define a tubular valve sleeve when said first fold is folded, said valve sleeve being positioned at an unsealed edge of the end flap.

3. A flattened bag as claimed in claim 2 and further comprising a tacking seal at each end of said valve flap, a third line of sealing along said unsealed edge of said end flap between said end flap and said valve flap, and a fourth line of sealing along said unsealed edge between said valve flap and the material forming said rectangle thereby to assist in forming said tubular valve sleeve when said first fold is folded.

4. A flattened bag as claimed in claim 3 in which third line of sealing terminates in a cross seal positioned short of said first fold line thereby to provide an air escape channel when said first fold is folded.

References Cited UNITED STATES PATENTS DAVID M. BOCKEVNEK, Primary Examiner.

US. Cl. XJR.

Images