Plastic bags

Claim 2

A plastic bag, provided adjacent the opening thereof, and on the inner surfaces of the opposite bag walls, with at least one male element which is engageable within an opening within at least one female element to close the bag, there being a yieldable diaphragm which extends across the opening in the female element and through which the male element must pass to enable closing of the bag whereby said male and female elements do not engage during manufacture, handling and stacking.

Claim 3

A plastic bag, provided adjacent the opening thereof, and on the inner surfaces of the opposite bag walls, with at least one set of male and female elements the male element of which is to be engaged inside the female element to close the bag, and means on said element set to prevent the engagement together of said male and female elements whereby said male and female elements do not engage during manufacture, handling and stacking, the female element comprising two superimposed grooves in parallel relationship and the male element having two ribs each one of which will co-operate with the corresponding groove in the female element, the corresponding groove and rib nearest the bag opening being so arranged that when the rib nearest the bag opening is engaged inside the groove sliding of the bag walls relative to one another in the location where the bag is closed is prevented while the corresponding groove and rib farthest away from the bag opening are so arranged that when the rib farthest from the bag opening is engaged inside the groove spreading away of the bag walls in the location where the bag is closed is prevented, the rib and groove nearest the bag opening being so arranged as to lock the other rib inside the associated groove when a pressure is exerted from inside the bag on the bag walls, said means for preventing the engagement of the male and female elements inside one another being arranged in that groove nearest the bag opening.

Claim 4

A plastic bag, provided adjacent the opening thereof, and on the inner surfaces of the opposite bag walls, with at least one set of male and female elements the male element of which is to be engaged inside the female element to close the bag, and means on said element set to prevent the engagement together of said male and female elements whereby said male and female elements do not engage during manufacture, handling and stacking, the female element comprising two superimposed grooves in parallel relationship and the male element having two ribs each one of which will co-operate with the corresponding groove in the female element, the corresponding groove and rib nearest the bag opening being so arranged that when the rib nearest the bag opening is engaged inside the groove sliding of the bag walls relative to one another in the location where the bag is closed is prevented while the corresponding groove and rib farthest away from the bag opening are so arranged that when the rib farthest from the bag opening is engaged inside the groove spreading away of the bag walls in the location where the bag is closed is prevented, the rib and groove nearest the bag opening being so arranged as to lock the other rib inside the associated groove when a pressure is exerted from inside the bag on the bag walls, said means for preventing the engagement of the male and female elements inside one another being arranged in that groove nearest the bag opening.

Claim 5

A plastic bag as claimed in claim 2, in which that rib nearest the bag opening has a cross-section in the shape of a triangle the base of which coincides with the bag wall while the corresponding groove with a triangular cross-section and the opening thereof lying substantially in parallel relationship with the bag wall has both sides thereof forming an angle which is slightly larger than the angle formed by both rib sides, that groove side nearest the bag opening having a dimension cross-wise to said groove which is larger than the dimension of the other groove side, that rib farthest away from the bag opening having an L-shaped cross-section the one leg of which extends substantially at a right angle to the bag wall while the other leg thereof extends toward the bag opening, the groove which cooperates with the L-shaped leg having an opening lying substantially at a right angle to the bag wall and facing inwards, being so arranged that when the bag is closed, the female element having a free edge which comes to lie within the angle formed by both rib legs, the size of said rib farthest from the bag opening being slightly smaller than the size of that rib nearest the bag opening as considered at right angle to the bag wall.

Claim 6

A plastic bag as claimed in claim 3, in which the cross-section of that rib nearest the bag opening is in the shape of an isosceles triangle.