Background Art In general, there is a difference in taste between a case that a user drinks as soon as opening a body cap of a carbonated water vessel and a case that a user drinks carbonated water again after keeping it during a predetermined period of time. The reason is that an amount of carbonic acid contained in carbonated water is reduced because most of carbonic acid is volatilized to the outside of the vessel the moment the body cap is opened.

Especially, in case that carbonated water shakes while being transported during driving or that carbonated water is frozen by outside temperature in the winter season, carbonic acid is leaked before the body cap is opened while the frozen water is thawed. Furthermore, in the above conditions, if the cap is opened, a volatilization amount of carbonic acid is increased.

The carbonated water from which carbonic acid is volatilized is nothing but sugared water, and thereby, the user may feel displeasure, and it may occur that the user throws away such carbonated water without drinking it.

Moreover, such carbonated water cannot satisfy the user who wants to be provided with more carbonic acid than the amount of carbonic acid contained in general carbonated water.

Disclosure of Invention Accordingly, it is an object of the present invention to provide a drinking water vessel, which can allow a user to selectively replenish carbonated water, from which carbonic acid is volatilized, with carbonic acid, or to add carbonic acid to an original amount of carbonic acid, thereby satisfying the user's desire and solving a problem of carbonic acid volatilization occurring during keeping or transporting carbonated water.

To achieve the above object, the present invention provides a drinking water vessel including a body cap removably connected to an opening part to keep drinking water for a long time, and a carbonic acid containing chamber formed on a prescribed portion of an outer circumference of the body cap for containing carbonic acid to supply drinking water with carbonic acid.

It is preferable that the carbonic acid containing chamber has a carbonic acid containing part opened at an upper end and having a predetermined space for containing carbonic acid, and an auxiliary cap for covering the carbonic acid containing part, the auxiliary cap having a pressurizing portion for pressurizing and opening the upper surface of the body cap to drop carbonic acid contained in the carbonic acid containing part into drinking water contained in the drinking water vessel.

Furthermore, it is preferable that the carbonic acid containing part has a screw thread at an outer circumference and the auxiliary cap has a screw thread at an inner circumference, so that the pressurizing portion of the auxiliary cap pressurizes the upper surface of the body cap while the carbonic acid containing part and the auxiliary cap are screwed with each other.

Moreover, it is preferable that a fastening band is provided between the body cap and the auxiliary cap to fasten the auxiliary cap to the body cap by coupling them with each other.

Additionally, it is preferable that the body cap has a cut portion being in the form of a curved line, which is opened at a remaining portion except a prescribed portion of an upper rim to prevent the cut portion pressurized and cut by the pressurizing portion from falling into drinking water.

Furthermore, it is preferable that the carbonic acid contain part has a jaw formed on the outer circumference to prevent the auxiliary cap from being released in a reverse direction after the upper surface of the body cap is opened completely by the auxiliary cap, and the auxiliary cap has a protrusion formed on the inner circumference, the protrusion responding elastically to the jaw so as to rotate in a forward direction but be prevented in reverse rotation.

Brief Description of the Drawings Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawing in which: FIG. 1 illustrates a perspective view of a drinking water vessel according to the present invention; FIGS. 2a and 2b illustrate partially sectional views showing a state that an auxiliary cap of the drinking water vessel of FIG. 1 is operated; FIGS. 3a and 3b illustrate partial plan views showing a state that the auxiliary cap of the drinking water vessel of FIG. 1 is operated ; and FIG. 4 illustrates a brief plan view of an upper surface of a body cap of the drinking water vessel.

Best Mode for Carrying Out the Invention The present invention will now be described in detail in connection with preferred embodiments with reference to the accompanying drawings. For reference, like reference characters designate corresponding parts throughout several views.

As shown in FIGS. 1 to 4, a drinking water vessel includes a carbonic acid containing chamber 10 provided to an upper surface of a body cap 12, a carbonic acid containing part 14 opened at an upper end and having a prescribed space, and an auxiliary cap 16 for covering the carbonic acid containing part 14 and pressurizing the upper surface of the body cap 12.

The carbonic acid containing part 14 is integrated with the upper surface of the body cap 16 and in the form of a cylinder opened at an upper portion, and has a screw thread 14a formed on an outer circumference to screw with the auxiliary cap 16. Additionally, the carbonic acid containing part 14 has a one- way saw-toothed jaw 14b formed at a lower end of the outer circumference for preventing the auxiliary cap 16 from being released conversely after being screwed.

The auxiliary cap 16 is in the form of a cap for covering the carbonic acid containing part 14, and has a screw thread 16b formed on an inner circumference for being screwed with the outer circumference of the carbonic acid containing part 14 and a pressurizing portion 16a extending from a central portion of a lower surface thereof to the upper surface of the body cap 12 for pressurizing the upper surface of the body cap 12 while the auxiliary cap 16 is wound in a forward rotational direction.

Moreover, the auxiliary cap 16 has a protrusion 16c formed on the lower end of the inner circumference thereof for rotating the auxiliary cap 16 in a direction that the auxiliary cap 16 is locked to the jaw 14b of the carbonic acid containing part 14 and for preventing reverse rotation of the auxiliary cap 16 in a reverse direction (releasable direction) of the above by catching it on the jaw 14b.

Here, the protrusion 16c is cut from the auxiliary cap 16 at an end and bent inwardly to be elastically folded and unfolded to the jaw 14b when the auxiliary cap 16 is rotated in the forward direction. Additionally, the protrusion 16c is supported by a spring (not shown) to prevent the reverse rotation by strongly supporting it to the jaw 14b.

Furthermore, a fastening band 20 is removably provided on the lower end of the auxiliary cap 16 for connecting the auxiliary cap 16 to the body cap 12 and fastening the auxiliary cap 16, and thereby the auxiliary cap 16 is not rotated.

Moreover, the body cap 12 has a cut portion 12a formed on the upper surface and being in the form of an opened curve, and the cut portion 12a is cut except a predetermined portion thereof when the pressurizing portion 16a presses it, so that the upper surface of the body cap 12 is opened and the cut upper surface hangs from the body cap 12 without falling into drinking water.

According to the above, in the drinking water vessel of the present invention, first, when the fastening band 20 between the body cap 12 and the auxiliary cap 16 is separated, the auxiliary cap 16 is in a rotatable condition.

Next, when the auxiliary cap 16 is rotated in the locked direction, the screw thread formed on the outer circumference of the auxiliary cap 16 is coupled with the screw thread formed on the outer circumference of the carbonic acid containing part 14 and rotated in the forward direction, and then, the pressurizing portion 16a pressurizes the upper surface of the body cap 12.

Here, the cut portion 12a, which is formed on the upper surface of the body cap 12, is separated from the body cap 12 by pressurizing force of the pressurizing portion 16a, so that the upper surface of the body cap 12 is opened and carbonic acid of the carbonic acid containing part 14 drops into drinking water to replenish drinking water with carbonic acid. The cut upper surface hangs from the body cap 12 without falling into drinking water.

Meanwhile, when the protrusion 16c and the jaw 14b are met while the auxiliary cap 16 is rotated on the outer circumference of the carbonic acid containing part 14 in the forward direction by screwing, the protrusion 16c of the auxiliary cap 16 is operated elastically and passes over the jaw 14b. When the auxiliary cap 16 is locked completely, the protrusion 16c of the auxiliary cap 16 is caught to the jaw 14b of the carbonic acid containing part 14 to prevent the reverse rotation, and then, the auxiliary cap 16 is rotated in integration with the body cap 12.

Industrial Applicability As described above, the drinking water vessel having the carbonic acid containing chamber formed in the upper surface of the body cap can allow a user to replenish drinking water with carbonic acid to satisfy the user's desire, prevent drinking water, from which carbonic acid is volatilized, from being thrown away, and keep the drinking water for a long time as it is.

While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.