Background of the Invention
1. Technical Field:
This invention relates to a new and improved snap on type plastic cap which fits on a plastic bottle neck such as a school milk bottle. The cap is characterized in that when the lower portion of the skirt thereof is torn off to permit removal of the cap, the remaining upper portion of the cap cannot be reattached to the bottle neck due to the formation of the inner surface of the upper skirt in opposed relation to the outer surface of the sealing flange spaced inwardly thereof so as to prevent the use of the cap as a reclosure cap.
2. Description of the Prior Art:
Caps generally similar to that of the present invention are the subject of many patents including the following, all of which have means permitting the use of the cap or a portion thereof as a reclosure cap. The neck shown in the accompanying drawings resemble a commercially available neck of the type shown in U.S. Pat. No. 4,784,296 which also shows single diameter cap skirts which are frangible on a circumferential tear line.
Other single diameter cap skirts which are frangible on a tear line are shown in U.S. Pat. Nos. 4,593,830, 4,691,834, and 4,815,617.
Dual diameter cap skirts which are frangible on a circumferential line between two diameters are shown in U.S. Pat. Nos. 4,232,229, 4,844,268, 4,911,316 and 4,934,546. In each of the above prior art patents, means is provided in the upper skirt for a complimentary fastening relation to an external rib on the neck of the bottle and such means is positioned below the top of the cap and above the circumferential tear line.
Summary of the Invention
The present invention comprises a cap which fits on the neck of a blow molded plastic bottle and is held thereon by an annular inturned rib on the inner surface of the tear skirt below the circumferential tear line which is defined by an annular area of weakness joining the upper annular edge of the tear skirt to the lower annular edge of the upper skirt of the cap. There is a vertical tear line which extends upward from the lower edge of the tear skirt adjacent a pull tab to the upper circumferential tear line which is used to remove the tear skirt along the circumferential tear line from the upper skirt of the cap to which it is attached. The upper skirt forms the annular peripheral edge of the cap and has its inner surface formed in a downwardly and outwardly curved surface which is progressively thinner toward its lower edge which with the upper edge of the tear skirt forms the circumferential tear line by reason of its thin wall formation. The upper inner surface of the tear skirt is formed with an upwardly and outwardly curving surface joining the area of the circumferential tear line which provides reinforcement of the lower portion of the upper skirt as long as the tear skirt is attached thereto and which permits outward flexing and distortion of the upper skirt when the tear skirt is removed completely or partially.
The annular sealing flange on the cap inwardly of the upper skirt is provided with a downturned and inturned curving surface with the area between the upper portions of the sealing flange and the upper skirt forming an annular cavity into which the upper end of the neck of a bottle having an external rib thereon is positioned when the non-replaceable snap on cap is positioned on a bottle neck. The resilient flexible oppositely curved areas of the upper portion of the snap on cap will not stay engaged on the upper end of the neck portion of a bottle when the tear skirt of the cap is removed.
Description of the Drawings
FIG. 1 is a vertical sectional view through a cap in accordance with the present invention;
FIG. 2 is a vertical sectional view through the upper portion of the cap with the tear skirt removed;
FIG. 3 is a side elevation of the cap with the tear skirt thereof partially removed from the upper portion; and
FIG. 4 is a side elevation of the cap and a portion of a bottle neck with parts broken away and parts in cross section showing the position of the elements of the cap on the neck of the bottle.
Description of the Preferred Embodiment
In FIG. 4 of the drawings, a bottle 10 has a neck portion 11 with an outturned rib 12 defining its upper end. A cap is positioned on the neck portion 11 and comprises a top 13 having an upper skirt 14 forming a peripheral edge thereof and a tear skirt 15 secured integrally to said upper skirt 14 by a circumferential thin wall forming a tear line 16. A tab 17 is integrally formed with the tear skirt 15 of the cap and a vertically extending thin wall forms a secondary tear line 18 between the lower edge of the tear skirt 15 and the tear line 16 and is located adjacent the tab 17.
Still referring to FIG. 4 of the drawings, it will be seen that the upper end of the neck 11 with its outturned rib 12 has been moved into position between the inner surface 20 of the upper skirt 14 and the outer surface 21 of an annular sealing flange 19, the space being smaller than the width of the upper end of the neck 11 and its outturned rib 12 so that distortion of the annular sealing flange 19 occurs.
By referring now to FIG. 1 of the drawings, a vertical sectional view of the new and improved snap on non-replaceable cap of the invention may be seen and it will be observed that the inner surface 20 of the upper skirt 14 is curved downwardly and outwardly from the top 13 of the cap to the thin wall which defines the tear line 16 that extends circumferentially around the cap completely or partially.
It will also be seen that the outer surface 21 of the annular sealing flange 19 is curved downwardly and inwardly from the top 13 so as to form a space between the oppositely disposed curving surfaces 20 and 21 that is smaller than the known width of the upper end of the neck 15 and its outturned rib 12 as heretofore described in connection with FIG. 4 of the drawings.
Still referring to FIG. 1, it will be seen that the tear skirt 15 has an inturned annular rib 22 positioned below an upwardly and outwardly curved annular surface 23 which joins the circumferential thin wall forming the tear line 16.
In FIG. 2 of the drawings, the upper portion of the cap of the invention is illustrated and comprises the top 13 with its peripheral edge defining the upper skirt 14 with its downwardly and outwardly curving surface 20 spaced with respect to the distortable annular sealing flange with its outer downwardly and inwardly curving surface 21 and it will be seen that when only the upper portion of the cap as illustrated in FIG. 2 of the drawings is pushed downwardly onto the upper end of the neck portion 11 with its outturned rib 12 on the bottle 10, its elasticity and resulting distortion will cause it to move upwardly partially away from the upper end of the neck portion 11 and its outturned rib 12 and therefore be incapable of being replaced thereon. The portion of the cap remaining after the tear skirt 15 thereof is removed, is therefore not capable of being used as a reclosure cap.
The present use of the invention makes this feature highly desirable as the cap is used as a non-replaceable snap on cap for school milk bottles which as known provide a small quantity of milk or other beverage, such as chocolate milk, orange juice, tomato juice and the like.
By referring now to FIG. 3 of the drawings, a front elevational view of the cap may be seen including the top 10, the upper skirt 14, the tear skirt 15 and the annular sealing flange 19 with its downwardly and inwardly curved surface 21 and wherein a portion of the tear skirt 15 has been removed by pulling the tab 17 away from the remainder so as to cause separation at the vertical thin wall defining the secondary tear line 18 and continuing around the thin wall defining the tear line 16. The inturned annular rib 22 may also be seen in its position below the downwardly and outwardly curved inner surface 20 of the upper skirt 14.
It will thus be seen that a non-replaceable snap on cap for plastic bottles and the like has been disclosed which incorporates a novel construction serving the dual purpose of assisting in retaining the cap in position on the neck of a bottle of known configuration by reason of the ability of the upper skirt 14 and the annular sealing flange 19 to require distortion when in position on the neck portion of a bottle and to resist attempts to replace the upper portion of the cap on the neck portion of a bottle when the upper portion is separated from the tear skirt thereof.