Cork cap

Abstract: A cork cap (27) having a head (11) and a leg (12) and adapted to be inserted in a bottle mouth (14). A cork (24) is press-fitted in the cap so that its bottom end protrudes from the bottom of the leg (12) and is pressed against the inner surface of the bottle mouth to seal the bottle mouth. The cork (24) can be pulled out by pulling the cork cap (27) while twisting it. Protrusions (25,26) are formed on the inner periphery of the tapered inner surface of the head between adjacent ones of a plurality of vertical ribs. The protrusions bite into the cork (24), thus keeping the cork (24) strongly coupled to the cork cap (27) even when the latter is pulled and twisted. Thus, the cork can be reliably pulled out together with the cork cap by twisting and pulling only the cork cap (27).

Description: BACKGROUND OF THE INVENTION This invention relates to a cork cap which is inserted in a bottle mouth before plugging a cork. Once the cork is plugged, the bottle mouth is completely sealed as with an ordinary bottle plugged solely with a cork. The cork can be pulled out together with the cork cap simply by pulling the cork cap without using a corkscrew or any other bottle opener. The inventor of this application proposed a cork cap of the above-mentioned type which makes it possible to pull out a cork plugged in e.g. a wine bottle simply by pulling the cork cap with both hands without using a cork screw (Examined Japanese Utility Model Publication 4-27836 and Unexamined Japanese Patent Publication 8-40446). Fig. 10 shows this cork cap. It is a plastic molding comprising a head 2 having an outer diameter greater than the inner diameter of a bottle mouth 1, and a leg 3 provided concentrically with the head 2 and having an outer diameter substantially equal to the inner diameter of the bottle mouth 1. The entire length of the cork cap, i.e. the sum of the lengths of the head 2 and the leg 3, is shorter than the length of the cork 4. The cork 4 is press-fitted into a hole 5 formed through the head 2 and the leg 3. Part of the hole 5 formed in the head 2 is tapered so that its diameter increases gradually upward. A plurality of vertical ribs 6 are provided on the inner periphery of the hole 5, extending from the head 2 to the leg 3. With the leg 3 of the cork cap inserted in the bottle mouth 1, the cork 4 is plugged into the bottle mouth 1. In this state, the portion of the cork 4 protruding downward from the leg 3 is pressed hard against the inner surface of the bottle mouth 1, sealing the bottle mouth 1. The cork 4 can be pulled out simply by holding the head 2 of the cork cap and pulling it. In the figure, a slit 8 is shown to be formed in a thin portion 7 of the leg 3. When a cork is plugged in a bottle mouth with the above cork cap inserted in the bottle mouth, the bottle mouth is sealed by the cork 4. The content of the bottle such as wine can perspire through the cork 4. The cork cap plays no role in these functions. Problem is how to pull out the cork reliably by pulling the cork cap. In the above conventional arrangement, the tapered inner surface of the hole formed in the head 2 mainly serves this purpose. That is, the tapered surface prevents the cap from separating from the cork when the former is pulled out. The vertical ribs 6 increase the frictional force between the cap and the cork when the former is turned. But it is desired to couple the cap and the cork more rigidly to prevent the cap from separating from the cork when the former is pulled. An object of this invention is to increase the resistance to the force that acts to separate the cork and the cork cap when a pulling force is applied to the latter by providing the cap with means that can strongly bite the cork. SUMMARY OF THE INVENTION According to this invention, there is provided a cork cap for a bottle comprising a head having an outer diameter greater than the inner diameter of the mouth of the bottle, a leg provided concentrically with the head and having an outer diameter substantially equal to the inner diameter of the bottle mouth, the head and leg having lengths, the sum of which is smaller than the length of a cork, the cork cap being formed with a hole extending through the head and the leg, the hole formed in the head being tapered radially outwardly from its bottom to top, a plurality of vertical ribs formed on the inner surface of the hole and extending vertically from the head to the leg, and means for preventing the separation of the cork cap from the cork when the cork cap is pulled to remove the cork, said means being formed so as to protrude radially inwardly from the tapered inner surface of said hole or from the surface of said respective vertical ribs at their portions disposed in said head. Instead of the horizontal ribs, protrusions may be formed each on the inner surface of the portion of the hole formed in the head between adjacent ones of the vertical ribs, each of the protrusions having a lower front surface extending vertically or tapered radially outwardly from its bottom to top, and an upper front surface connecting at its bottom with the top of the lower front surface along a horizontal ridge and tapered radially outwardly toward its top from the ridge. Instead of such horizontal ribs or protrusions, each of the vertical ribs may be formed with a radially inwardly protruding step at its portion disposed in the head. In any of the arrangements, the cork can be more strongly coupled to the cork cap than in conventional arrangements. Other features and objects of the present invention will become apparent from the following description made with reference to the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partially cutaway perspective view of a first embodiment; Fig. 2A is a sectional view of the same; Fig. 2B is a partial sectional view taken along line b-b of Fig. 2A; Fig. 3 is a partial enlarged sectional view of the same showing how it is used; Fig. 4 is a partially cutaway perspective view of a second embodiment; Fig. 5A is a sectional view of the same; Fig. 5B is a sectional view taken along line b-b of Fig. 5A; Fig. 6 is a partial enlarged sectional view of the same showing how it is used; Fig. 7 is a partially cutaway perspective view of a third embodiment; Fig. 8A is a sectional view of the same; Fig. 8B is a sectional view taken along line b-b of Fig. 8A; Fig. 9 is a partial enlarged sectional view of the same showing how it is used; Fig. 10A is a sectional view of the prior art; and Fig. 10B is a sectional view of the same as used with a cork. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Figs. 1-3 show a cork cap of the first embodiment, which is, like the conventional cap, a plastic molding. It comprises a head 11, a leg 12 concentrically provided at the bottom end of head 11, and a cover 13 integrally connected to the top of the head 11. The head 11 is tapered so that its inner diameter is greater at the top than at the bottom. Its outer diameter at its bottom is greater than the inner diameter of a bottle mouth 14 (see Fig. 3) so that the bottom of the head 11 rests on the bottle mouth 14. The leg 12 is cylindrical and has an outer diameter substantially equal to the inner diameter of the bottle mouth 14. A hole 15 is formed through the head 11 and the leg 12. Its portion formed in the head 11 is tapered so that its diameter increases gradually upward. Its portion at the bottom of the leg 12 is tapered so that its diameter increases gradually downward. Thus, the wall of the leg 12 is thin at the bottom. The thin portion 16 of the leg is formed with a plurality of slits 17 extending vertically from the bottom end of the leg. A V-shaped groove 18 is formed so as to connect with the top end of each slit 17. The cover 13 comprises a flange 19 extending radially outwardly from the top of the head 11, and a cylindrical portion 21 extending downward from the outer edge of the flange 19. The cylindrical portion 21 extends to a level near the top end of the thin portion 16 of the leg 12, covering the bottle mouth 14 (Fig. 3). A nonslip surface 22 is formed on the outer periphery of the cylindrical portion 21. Reinforcing radial ribs 23 are provided, circumferentially spaced from each other, between the outer periphery of the head 11 and the inner periphery of the cylindrical portion 21 (Fig. 2B). The sum of the lengths of the head 11 and the leg 12 is shorter than the length of the cork 4 (Fig. 3). A required number of vertical ribs 25 are formed at required circumferential intervals on the inner periphery of the head 11 and the leg 12. The ribs 25 extend to the top end of the thin portion 16 of the leg 12. They have a triangular section (Fig. 2B). Horizontal ribs 26 are formed on the inner periphery of the head 11 between and spaced from the adjacent vertical ribs 25. The horizontal ribs 26 have a triangular section with a horizontal bottom 26a and an inclined top surface 26b, as shown in Fig. 2A. They are slightly higher than the portions of the vertical ribs 25 at the level of the horizontal ribs 26 (Fig. 2B). In use, with the leg 12 of the cork cap 27 (Fig. 3) inserted in the bottle mouth 14 and the head 11 resting on the bottle mouth 14, the cork 24 is plugged in. The cork 24 is an ordinary column-shaped cork. It is compressed when it passes through the leg 12. When its bottom end 28 protrudes from the bottom end of the leg 12, it expands to be pressed hard against the inner periphery of the bottle mouth 14, sealing the bottle mouth. If the bottle mouth 14 is slightly oversized, the slits 17 will widen and the V-shaped grooves 18 may be torn, thereby spreading the leg's bottom. As the cork 24 is pushed into the bottle mouth, it is deformed along the tapered inner surface of the head 11, while the vertical and horizontal ribs 25 and 26 bite into the cork 24. The tapered inner surface and the horizontal ribs 26 formed on the head 11 will keep the cork strongly coupled to the cork cap when the cork cap 27 is pulled up. The vertical ribs 25 allow the cork 24 to rotate with the cork cap 27 when the latter is twisted. Thus, by pulling the cork cap 27 while twisting it by hand, the cork 24 together with the cork cap 27 can be pulled out of the bottle mouth 14. The horizontal ribs 26 of the first embodiment are inversely tapered, so that a complicated mold has to be used to form the cork cap 27. The second embodiment shown in Figs. 4-6 is free of this problem. In the second embodiment, protrusions 31 are formed on the inner periphery of the head 11 between the adjacent vertical ribs 25. They are long in the vertical direction and have a constant width over the entire length. Each protrusion 31 has a lower front surface 33 extending vertically upward from the bottom end of the head 11 (Fig. 5A), and a tapered upper front surface 34 extending obliquely upwardly so that its top end is radially outside of its bottom end. A horizontal ridge 32 is defined between the lower and upper surfaces 33 and 34. The lower front surface 33 may be tapered radially outward from its bottom toward the ridge 32. Since the protrusions 31 are not inversely tapered, the cork cap of this embodiment can be formed using a less complicated mold. The upper front surface 34 of each protrusion 31 serves to keep the cork 24 strongly coupled to the cork cap when the latter is pulled. Otherwise, this embodiment is the same as the first embodiment. Figs. 7 to 9 show the third embodiment, in which each vertical rib 25 has a radially inwardly extending step 35 midway of its length. Since the ribs 25 have a V-shaped cross-section, the steps 35 are also V-shaped as viewed from top (Fig. 8B). The steps 35 also serve to keep the cork strongly coupled to the cork cap when the latter is pulled. Otherwise, this embodiment is the same as the first embodiment. The horizontal ribs, protrusions and steps formed on the inner periphery of the head of the cork cap increase the force with which the cork is coupled to the cork cap when the latter is pulled, thus making it possible to pull out the cork together with the cap with high reliability.

Claims: A cork cap for a bottle comprising a head (11) having an outer diameter greater than the inner diameter of the mouth (14) of the bottle, a leg (12) provided concentrically with said head (11) and having an outer diameter substantially equal to the inner diameter of the bottle mouth (14) said head (11) and leg (12) having lengths, the sum of which is smaller than the length of a cork, said cork cap being formed with a hole (15) extending through said head (11) and said leg (12), said hole (15) formed in said head being tapered radially outwardly from its bottom to top, a plurality of vertical ribs (25) formed on the inner surface of said hole (15) and extending vertically from said head to said leg characterized in that , means (26, 31, 35) are provided for preventing the separation of said cork cap from the cork when said cork cap is pulled to remove the cork, said means being formed so as to protrude radially inwardly from the tapered inner surface of said hole (15) or from the surface of said respective vertical ribs (25) at their portion disposed in the head. The cork cap as claimed in claim 1, wherein said means comprises a plurality of horizontal ribs (26) each formed on the inner surface of said hole formed in said head between adjacent ones of said vertical ribs (25). The cork cap as claimed in claim 1, wherein said means comprises a plurality of protrusions (31) each formed on the inner surface of said hole formed in said head between adjacent ones of said vertical ribs (25), each of said protrusions (31) having a lower front (33) surface extending vertically or tapered radially outwardly from its bottom to top, and an upper front surface (34) connecting at its bottom with the top of said lower front surface along a horizontal ridge (32) and tapered radially outwardly toward its top from ridge and tapered radially outwardly toward its top from said ridge. The cork cap as claimed in claim 1, wherein said means comprises a radially inwardly protruding step (35) formed on each of said vertical ribs (25) at its portion disposed in said head.

Inventors: HIROTA KOJI, HIROTA, KOJI
Applicants: HIROTA KOJI, HIROTA, KOJI
Application year: 1997
Main classification: B65D39
IPC codes: B65D39, B67B7