Easy opening crown cap

Abstract: A crown cap for sealing bottles comprising a cap body (1) including substantially a flat top (7), a crimped portion (2) formed on the periphery of the cap body (1) and an outwardly extending pull piece (3) integrally connected to a part of the crimped portion (2) and having a width of about 5 to 7 included teeth (5). A small notch (8) is formed at the intersection between the basal end of the pull piece (3) and the crimped portion (2), from which a score line extends upwardly along the crimped portion (2) and passes slightly across the peripheral curved portion of the flat top (7) and has an appropriate depth. The pull piece (3) is formed at the margin with a pleated portion to strengthen the rigidity. The score line may be curved at the terminal end towards any of one side on the right or the left and may be additionally provided with a short score line perpendicularly of each other. In this construction, the crown cap can be easily opened out from the mouth of a bottle by pulling the pull piece (3) over with fingers.

Description: The present invention relates to a crown closure according to the preamble of claim 1, particularly to an easy opening crown cap for sealing bottles, which is totally different from the conventional hand-open types where the pull-to-open or tearing off technical art is followed, and employs a novel pull-it-over technical concept. The crown cap of the present invention includes a cap body having substantially a flat top, a skirt portion to be crimped on a bottle formed on the periphery of the cap body, and an outwardly extending finger tab integrally joined to a part of the skirt portion. Crown caps, being the most simple and economic in construction, are imployed for sealing liquid containers like wine bottles, sauce bottles or aerated water bottles. In general, a crown cap is made of a tinned plate in a cap shape, and relying totally on the twenty-one included teeth in the skirt portion, closely embraces the protruding ring at the mouth of the bottle by flexibility and elasticity of the metal and tightly seals the mouth of the bottle to provide air-tightness or liquid-tightness due to the gasket or disc inside its flat top. Although the crown cap is simple in construction and has a wonderful function, however, on opening the bottle, a tool such as an opener, is required for pulling the included teeth apart from the protruding ring at the mouth of the bottle in order to separate the cap from the bottle mouth. There has since been much research with regard to how a crown cap can be easily opened out without having to rely on a tool. Among the prior art in the field are, for example, GB-A-1 466 317, US-A-3 382 997 and US-A-3 937 349, which disclose different designs of crown closure with easy open means for bottles. However, since most of these crown caps are formed by stamping of tinned plate, which is of relatively hard material, to split open the caps with a finger tab or pull ring has not been that simple, particularly because the purpose of opening the bottle cannot be accomplished if the pulling force applied is insufficient. When the finger tab is lifted forcefully because of difficulty in the pulling, the various projections and the cut portions on the crown cap itself and on the finger tab are all likely to cause cuts to fingers and uneasiness to the user. Furthermore, when the finger tab which has broken the skirt portion off is further pulled upward, the remainder skirt portion, that is, the remainder portion of the included teeth, is still hooked to the protruding ring at the mouth of the bottle and will thus require further application of force for pulling upward in order to separate the cap from the bottle mouth. Particularly, the said included teeth of the skirt portion that have been torn apart are of considerable sharpness, which, either during the opening of bottle or upon being discarded away, are likely to cause cuts to poeple. Still further, when the crown cap which has been torn open is to re-seal the mouth of the bottle, it requires that the parts which have been pulled open or the other deformed parts be made to return to their original condition in order to achieve the result of resealing of the bottle temporarily. US-A-2 156 258 (corresponding to the preamble of claim 1) discloses a bottle cap having a disc top, a corrugated flared skirt adapted to be crimped over the bead of the bottle neck, a sealing disc confined against the bottom face of the disc top, and a rolled up edge portion forming a crescent shaped grip adapted to be manually grasped and pulled upward to dislodge the cap from the bottle neck. However, tearing scores of this cap are formed at two locations, namely diametrically opposite points in the skirt. With this bottle cap, it will be unlikely to re-seal the bottle for temporary storage because the split on the bottle cap will be too large after opening for the first time. US-A-2 780 380 also discloses a hand-removable crown cap provided with a tear tab and a slit, in which the tear tab projects from the edge of the skirt immediately adjacent the slit, while the slit extends uninterruptedly from the skirt's lower edge, along the crest of one of the skirt flutes and radially inward across the top, terminating appreciably short of the center of the top plate. This cap is still unlikely to reseal the bottle because the cap will have been torn by the progressive shearing action for opening the cap. In view of the above shortcomings, an object of the present invention is to provide an easy opening crown cap where during its opening from the bottle damage to the crown cap will be kept to the minimum, that is, there being only one score line which passes from the edge of the skirt portion of the cap body to just beyond the peripheral curved portion, and thereby when the crown cap is pulled open, the split on the crown cap will not go beyond for about 5mm in width and when the cap becomes separated out from the mouth of the bottle there will be almost no deformation in the crown cap. A further object of the present invention is to provide an easy opening crown cap in which the finger tab is broadened in width and which, upon turning into a curved surface on being sealed to the mouth of a bottle becomes a rigid lug piece. A further object of the present invention is to provide an easy opening crown cap in which the broadened finger tab has only one score line whereby forces can be focused on the one line, and also the score line is shortened to just pass across the curved portion and a small notch, from which the score line extends upwardly, is formed at the intersection point between the basal end of the finger tab and the skirt portion and at one or the other side of the finger tab. An additional object of the present invention is to provide an easy opening crown cap which, owing to the small pulling force required to be applied with finger and the very little deformation resulting to the cap, is the most safe and easy to operate for people of all ages. Another object of the present invention is to provide an easy opening crown cap in which the pulling over action not only breaks the skirt portion but is also able to push the cap off the mouth of the bottle. A further object of the present invention is to provide an easy opening crown cap which, because of less damage and no deformation when being opened out from the bottle, can still be retained on the mouth of the bottle for temporary sealing of the bottle without having to reshape the cap. These objects are solved in accordance with the teaching of claim 1. Other aspects and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment thereof in connection with the accompanying drawings, in which: Fig. 1 is a perspective view of a crown cap constructed in accordance with the present invention, showing the cap prior to being sealed to a bottle; Fig. 2 is a perspective view of the crown cap of Fig. 1 after the cap has been turned over and the interior gasket partially cutaway; Fig. 3A is a top view of the crown cap shown in Fig. 2, the interior gasket partially cutaway and the score line defined on the right side thereof; Fig. 3B is a top view of the crown cap shown in Fig. 2, the interior gasket partially cutaway and the score line defined on the left side thereof; Figs. 4A to 4J are schematic views of the crown cap having the essential portion partially cutaway and showing the score line formed in various ways of arrangement; Fig. 5 is a perspective view of the crown cap after the cap has been sealed to the mouth of a bottle; Figs. 6A and 6B are schematic views showing stages of pulling the cap open from the mouth of the bottle in one embodiment; and Figs. 7A and 7B are schematic views showing stages of pulling the cap open from the mouth of the bottle in another embodiment. Referring now to Figs. 1 through 3, there is shown the outer appearance of a crown cap of the present invention before sealing to a bottle. The crown cap comprises a cap body 1 having the periphery formed in a skirt portion 2 to be crimped on a bottle, a finger tab 3 extending outwardly from a part of the skirt portion 2 and a circular gasket 4 mounted on the inside surface of the cap body 1. The skirt portion 2, in general, has, as in a standard conventional crown cap, twenty-one included teeth 5. The finger tab 3 constitutes the essential part for efficiency of the crown cap of the present invention, and in order to achieve the pull-to-open function, this finger tab 3 must be integrally joined to the skirt portion 2. To ensure that the finger tab 3 will not bend along the lower edge of the skirt portion 2, width of the finger tab 3 preferably extends across five to seven included teeth 5 or occupies about one-third of the periphery of the crown cap and length of the finger tab 3 is about 2 to 3 times the height of the included teeth. Furthermore, the peripheral edge of the finger tab 3 is rolled over to form a pleated edge 6 to thereby strengthen the finger tab 3 and prevent cuts to hands because of sharp edges. Before the crown cap is sealed to the mouth of a bottle, this finger tab 3 and the whole lower edge of the skirt portion 2 are located on about the same plane and together lie somewhat parallel to the flat top 7 of the cap, and also during this time, no hardness force is formed in the finger tab 3. However, when a crown cap is compressed by a bottle capper, the finger tab 3 is pressed to assume an arched curvature shape as shown in Fig. 5, and consequently, hardness is greatly strengthened in the finger tab 3 whereby the tab forms a rigid pull piece. At the intersection point between the basal end of the finger tab 3 and the skirt portion 2 at one or the other side there is formed a small notch 8. From the top end of this small notch 8 is provided a score line 10 which extends upwardly from the small notch 8 along the skirt portion 2 and passes across the peripheral curved portion 9 of the flat top 7 and terminates just inside the outer margin of the top portion of the flat top 7. The reason that this score line 10 must pass a little across the curved portion 9 is because the curved portion 9 is formed by stamping to form a reinforced portion which will not easily break upon being pulled open. Depending on quality of the material of the metal and thickness, the depth of the score line 10 generally is about half the thickness of the crown cap and should be appropriate so that the score line 10 can just be broken out upon being pulled up. Although the skirt portion 2 is not directly concerned with air-tightness or liquid-tightness of the bottle, it will however increase the degree of easiness in the pulling open of the finger tab 3 if the terminal end of the score line 10 is cut to form a score line to extend towards the flat top 7 from the small notch 8 along the intersection point between one side face of the finger tab 3 and the skirt portion 2. Again, although the score line 10 may be formed on the outer surface or the inside of the crown cap, it will however be more particularly useful and of esthetical beauty if the said score line 10 is defined on-the inside where, because there is coverage of the gasket 4, the line will not be exposed. Furthermore, the shape and arrangement of the score line 10 may be such as shown in Figs. 4A through 4J wherein the terminal end of the line assumes a T-shape with formation at the tip thereof of a short perpendicular score line or a straight line only or is curved slightly towards the right or the left after the score line 10 has reached the flat top 7, or that the score line 10 with formation of the short perpendicular score line near the terminal end thereof assumes a cross-shape. This score line 10 may also vary in shape and arrangement in different ways. By such an arrangement and shape of the score line 10, it further facilitates the breaking off along the score line 10 on pulling over and pushing open of the crown cap from the bottle. When a crown cap of the present invention which has been sealed to the mouth of a bottle as depicted in Fig. 5, is to be opened out from the bottle, this can be performed by pulling the finger tab 3 over with tip of the forefinger while the thumb being pressed against the flat top 7 as shown in Figs. 6A and 6B, or the other way with tip of the thumb pulling the finger tab 3 and the forefinger being pressed against the flat top as illustrated in Figs. 7A and 7B. In whichever way it may be, when sufficient force has been applied by the finger, this force will focus on the weakest point of notch 8 of the score line 10, thereby breaking off the cap along the score line 10 till to the end portion of the line, that is, to the curved portion 9. This kind of destruction is a kind of breach rather than a tearing off, for there is still material around all sides of the crown cap and the cap is almost without any deformation. The splitting open of this score line 10 release simultaneously the forces on the skirt portion 2 embracing the mouth of the bottle. At the same time, by way of the pulling over force, the valley of inclined teeth of the skirt portion 2 is pulled over the protruding ring at the mouth of the bottle and the crown cap can thus be opened out with great ease. In accordance with the basic concept underlying the principle of the invention, it is only necessary to pull open a very small part of the skirt portion 2 enough for the valley of included teeth to slip over the protruding ring at the mouth of the bottle, whereas in the conventional type the opening is performed by tearing off the self open crown cap. According to the present invention, the rationale is therefore similar to the use of a cap opener in forcing the valley of included teeth to slip over the protruding ring at the mouth of the bottle. In use of the crown cap of the present invention, since damage and deformation is the least, the user will not have to worry about being accidentally cut. With regard to being easily opened on pulling over and having less damage and more safety in the operation, this crown cap should prove to be a most practically useful model.

Claims: A crown cap for sealing bottles comprising a cap body (1) including substantially a flat top cap portion (7), a skirt portion (2) to be crimped on a bottle formed on the periphery of said cap body (1), and an outwardly extending finger tab (3) integrally joined to a part of said skirt portion (2), whereby said finger tab (3) is provided laterally at the basal end connected to said skirt portion (2) with notch means (8), and at the tip of said notch means (8) with a score line (10) passing upwardly from said notch means (8) along said skirt portion (2), characterized in that said notch means is only one small notch (8) provided on only one side of said finger tab (3), said score line (10) extends to a point on said substantially flat top cap portion (7) at a position slightly across the peripheral curved portion (9) of the flat top cap portion (7) whereby when the cap body (1) is pulled open causing a split on the crown cap this split does not exceed 5 mm in width and is defined as having a depth of about half the thickness of the crown cap, and that the finger tab (3) is formed along its peripheral edge with a pleated portion (6) having a double fold configuration to strengthen the rigidity of said finger tab (3). A crown cap according to claim 1, characterized in that the small notch (8) is located on the valley of included teeth (5) of the skirt portion (2) of the crown cap. A crown cap according to claim 1, characterized in that the finger tab (3) has a width including about 4 to 7 included teeth (5) and a length being about 2 to 3 times the height of the included teeth. A crown cap according to claim 1, characterized in that the depth of the score line (10) joining to the small notch (8) is about half the thickness of the crown cap. A crown cap according to claim 1, characterized in that the section of the score line (10) reached the flat top (7) cap portion is curved at its terminal end thereof and towards the right or the left side. A crown cap according to claim 1, characterized in that on the score line (10) there is another short score line. A crown cap according to claim 6, characterized in that the short score line is a cross or a line section or an arc or a dot.

Inventors: HSU SHIH-CHEN, HSU, SHIH-CHEN
Applicants: HSU SHIH CHEN, HSU, SHIH-CHEN
Application year: 1989
Main classification: B65D41
IPC codes: B65D41