The present invention relates in general to the reclosable bag art, wherein bags made from sheet material and more particularly plastic film are equipped with reclosable extruded zipper means wherein one bag wall has adjacent to the bag opening a zipper strip which has profile means interlockable with complementary profile means on the opposite bag wall. More particularly, the invention relates to the zipper means and new and improved profile structure therefor.
The present invention is particularly directed to extruded zippers of the kind wherein a single generally hook-shaped profile rib on one zipper strip is releasably interlockable within a single generally channel shaped or grooved complementary profile having confronting spaced generally hook-shaped lip means releasably interlockable with the hook-shaped rib profile. A prior art example of such zipper structure is seen in U.S. Pat. No. 4,101,355.
The foregoing zipper structure is distinguishable from zipper structures of the multi-hook and groove type as exemplified in U.S. Pat. No. 4,430,070, wherein both of the releasably interlockable profile strips have similar profile rib hooks and complementary grooves shaped for mating with the profile hooks of the companion strip.
A problem encountered with the single rib and groove profile zipper strips that is not encountered with the multicomplementary rib and groove zipper strip resides in that whereas the multi groove profile presents a fairly stable, generally square or rectangular shape resisting deformation in handling, the single hooked rib profile has heretofor generally lacked such stability, though some attempts have been made to correct this problem, as in copending application U.S. Ser. No. 866,917 filed May 27, 1986.