Closure for Sliderless Zipper Bags

A. Field of Invention

This invention pertains to the art of extruded reclosable bags and more particularly to a reclosable bag having fastener profiles with finger guides for interlocking the profiles and secondary closure means for insuring that the interlocked profiles do not open inadvertently.

B. Description of the Prior Art

Reclosable bags used for example for storing household goods are typically made of polyethylene. As shown in U.S. Pat. No. 3,416,199 to Imamura commonly assigned with the present invention, a reclosable bag may be formed of two opposed walls equipped at the mouth with fastener profiles. These profiles include a male profile attached to one wall and a female profile on the other wall. The profiles are shaped so that when they are aligned and pressed together into an engaging relationship they form a continuous closure for the bag. The bag may be opened by pulling the walls apart thereby separating the profiles. Various geometric shapes and arrangements for such profiles are shown in Re. U.S. Pat. Nos. 28,969; 3,323,707; 4,212,337; 4,363,345; 4,561,108; and 4,812,056. In addition U.S. Pat. Nos. 4,736,496 and 5,012,561 disclose reclosable bags with profiles and internal ribs adjacent to the profiles. U.S. Pat. No. 4,822,539 discloses a reclosable bag with interlocking profiles, internal guiding ribs disposed adjacent to the profiles, and stabilizing beams disposed on an outside surface of the bag wall. U.S. Pat. No. 3,338,285 discloses a reclosable bag having several parallel interlocking male and female profiles. In general, the profiles must be such as to provide relatively high resistance to opening from inside the bag while rendering the bag relatively easy to open from the outside.

One problem with the prior art reclosable bags is that their closures are sometimes not strong enough to hold large or heavy articles, and as a result the profiles may separate inadvertently during use. A further problem is that it is sometimes difficult to close such bags particularly large bags where the fingers of a user may drift off the profiles resulting in the closing pressure not being directly applied to portions of the closures.

In view of the above, an objective of the present invention is to provide a reclosable bag with improved closure means resistant to inadvertent opening.

A further objective is to provide a reclosable bag with guide means which guide the fingers of user when closing the bag whereby the bag can be easily and securely closed.

Other objectives and advantages of the invention will become apparent from the following description. A reclosable bag constructed in accordance with this invention includes a front wall and a rear wall joined to form an enclosure with a mouth defined by wall edges at the top of the bag and male and female profile means for selectively opening and closing said mouth. The male and female profile means form a primary closure for the bag. Secondary closure means are provided to maintain the primary closure means in a closed position and to prevent the inadvertent opening. The bag may also include guide means disposed opposite to the profile means for guiding a user's fingers along the profile means. Advantageously the guides also define hinging regions for the secondary closure means.

FIG. 1 shows a plan view of a reclosable bag constructed in accordance with the invention; and

FIG. 2 shows an enlarged side sectional view of the bag opening.

Referring now to the drawings, a reclosable bag 10 constructed in accordance with this invention includes front and rear walls 12, 14 seamed along three edges thereby forming an enclosure with an opening or mouth 16 along the top or fourth edge 18. The bag 10 is preferably made of a thermoplastic material such as polyethylene by extrusion. Attached to internal faces, walls 12 and 14 are male and female profiles 20, 22 respectively which extend continuously from side to side of the bag. The profile serves to close the bag opening 16 when they are interlocked as shown in FIG. 2.

On the outside face of wall 12 two ribs 24, 26 are located, and placed parallel to member 20 to thereby define a valley 28 disposed behind member 20. A third rib 30 much smaller than ribs 24, 26 is disposed in valley 28, directly behind male profile 20 and serves to provide a stabilizer for male member 20.

The spacing between ribs 24 and 26 and the sizing of ribs 24, 26 and 30 is such that valley 28 is sized and shaped to act as a finger guide for the end user of the bag 10. Thus, as the user passes his finger in the valley the user's finger is directed towards the optimum position for applying pressure for forcing the profiles 20, 22 together and insure that the profiles interlock properly across the entire width of the bag. Male profile 20 and female profile 22 are of the asymmetric arrowhead construction disclosed in Re. U.S. Pat. No. 28,969 and serve to form the primary closure means for bag 10. However, whereas the conventional female profile includes only internally directed hooks 33,35 extending from arms 22' and 22" for engagement with the internally directed barbs 37,39 of the conventional male arrowhead profile, the female profile 22 of the present invention also includes externally directed hooks 40,42 extending from arms 22' and 22". In addition, two parallel beams 32, 34 are provided on each side of male profile 20, extending from the internal face of wall 12. These beams 32, 34 have a generally L-shaped cross-section terminating in short latching hooks or stubs 36, 38 respectively which are generally parallel to wall 12 but are slightly angled. The purpose of these beams 32, 34 is to limit the movement of the arms 22', 22" of female profile 22. Preferably stub 42 is angled slightly with respect to stub 38, whereas stubs 40 and 36 are generally parallel as shown in FIG. 2. Stubs 40, 42 cooperate with beams 32, 34 to form an interlocking interconnection when snapped together to provide a secondary closure means for bag 10. In this connection, as with the primary closure means the secondary closure means is asymmetric resulting from the taper to stud 42 so that a greater disengagement force is required to be applied on the inside of the bag than is required to be applied on the outside of the bag to disengage the secondary closure. In this manner, the resistance to inadvertent opening of the bag from the inside is enhanced.

Bag 10 is normally opened by gripping edges 18, 18' on the outside of the bag and pulling them apart. This action causes beams 32 and 34 to pivot away from the female profile 22, as shown by arrows A and B thereby disengaging the secondary closure and also separates the barbs 37,39 of the male arrowhead member from the stubs 33,35 of the female member allowing the female member 22 to disengage from the male member 20. Importantly ribs 24 and 26 define hinging zones 44, 46 on wall 12 which allow the beams 32,34 to pivot easily to enable the action described above.

Bag 10 may be generated unitarily for example by extruding the walls of the bag 12, 14, the profiles 20, 22, the ribs 24, 26, 30 and beams 32, 34 integrally as shown in FIG. 2. Alternatively the closures may be provided as strips 50 to be bonded to sheets of bag forming material at some stage in the bag forming operation.

Obviously numerous modifications may be made to this invention without departing from their scope as defined in the appended claims.