US20150289694A1

US20150289694A1 - Contaminant backflow prevention straw and contaminant backflow prevention device having the same

Info

Publication number: US20150289694A1
Application number: US14/441,848
Authority: US
Inventors: Young-joo Shin; Hyung-Tae Moon; In Young Kim
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-11-28
Filing date: 2013-11-22
Publication date: 2015-10-15
Also published as: WO2014084554A1; KR101379233B1

Abstract

The present invention relates to a contaminant backflow prevention straw and a contaminant backflow prevention device including the same, the straw including: a sucking portion for sucking a beverage stored in a container therein; a discharging portion for discharging the beverage sucked through the sucking portion; a contaminant discharging portion formed between the sucking portion and the discharging portion to discharge the beverage flowing backward from the discharging portion to the sucking portion to the outside of the container; and a guide blocking screen formed at an intersecting portion of the sucking portion, the discharging portion, and the contaminant discharging portion to allow the sucking portion and the discharging portion to communicate with each other during the suction of the beverage and to allow the discharging portion and the contaminant discharging portion to communicate with each other during backward flowing of the beverage.

Description

TECHNICAL FIELD

The present invention relates to a contaminant backflow prevention straw and a contaminant backflow prevention device having the same, and more particularly, to a contaminant backflow prevention straw and a contaminant backflow prevention device having the same that prevents a beverage in which contaminants are contained from being accommodated in a container while the beverage stored in the container is being sucked.

BACKGROUND ART

Generally, a straw has a passage formed therein to pass a beverage therethrough, and if the front end of the straw pulls by a user's lips in the state where the rear end of the straw is inserted into the beverage stored in a container, the beverage is sucked in the user's mouth through the passage of the straw.
If the user's lips are free from the straw during the beverage is sucked through the straw, however, the beverage sucking in his or her mouth moves back to the container, together with his or her saliva, thus deforming the beverage or making the beverage unsanitary.
If the beverage in one container is sucked through a plurality of straws used by different users, their saliva are mixed in the container. For example, if one beverage container is used together with the person who is infected with pathogens, the beverage accommodated in the container becomes infected with the pathogens, thus making the beverage unsanitary to cause even persons who are healthy to be infected seconarily with the pathogens.

DISCLOSURE

Technical Problem

Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a contaminant. backflow prevention straw that is configured to have a contaminant discharging portion formed between a sucking port or; for sucking a beverage therein and a discharging portion for discharging the beverage therethrough and guide blocking screen formed at an intersecting portion of the sucking portion, the discharging portion, and the contaminant discharging portion, thus preventing the beverage in which contaminants are contained from being accommodated in a container while the beverage stored in the container is being sucked.
It is another object of the present invention to provide a contaminant backflow prevention device having contaminant backflow prevention straw that is configured to have a case having a storage space formed therein in such a manner as to be connected to the contaminant backflow prevention straw, thus storing and discharging a beverage in which the contaminants discharged through a contaminant discharging portion are contained, without having any separate accommodation parts.

Technical Solution

To accomplish the above-mentioned objects, according to a first aspect of the present invention, there is provided a contaminant backflow prevention straw including: a sucking portion for sucking a beverage stored in a container therein; a discharging portion for discharging the beverage sucked through the sucking portion; a contaminant discharging portion formed between the sucking portion and the discharging portion to discharge the beverage flowing backward from the discharging portion to the sucking portion to the outside of the container; and a guide blocking screen formed at an intersecting portion of the sucking portion, discharging portion, and contaminant discharging portion to allow the sucking portion and the discharging portion to communicate with each other during the suction of the beverage and allow the discharging portion and the contaminant discharging port ion to communicate with each other during backward flowing of the beverage.
To accomplish the above-mentioned objects, according to a second aspect of the present invention, there is provided a contaminant backflow prevention device including: a contaminant backflow prevention straw having a sucking portion for sucking a beverage stored in a container therein, a discharging portion for discharging the beverage sucked through the sucking portion, a contaminant discharging portion formed between the sucking portion and the discharging portion to discharge the beverage flowing backward from the discharging portion to the sucking portion to the outside of the container, and a guide blocking screen formed at an intersecting portion of the sucking portion, the discharging portion, and the contaminant discharging portion to allow the sucking portion and the discharging portion to communicate with each other during the suction of the beverage and to allow the discharging portion and the contaminant discharging portion to communicate with each other during backward flowing of the beverage; a container straw having one side disposed at the inside of the container and the other side connected to the sucking portion of the contaminant backflow prevention straw; and a case mounted on top of the container and including a straw passage formed on one side thereof to pass the container straw therethrough, a storage space formed therein to accommodate and store the beverage in which contaminants are contained flowing thereto through a coupling portion connected to the contaminant discharging portion of the contaminant backflow prevention straw, and a discharging outlet formed on the underside thereof to discharge the beverage in which the contaminants are contained accommodated in the storage space to the outside.
To accomplish the above-mentioned objects, according to a third aspect of the present invention, there is provided a contaminant backflow prevention device including: a contaminant backflow prevention straw having a sucking portion for sucking a beverage stored in a container therein; a discharging portion for discharging the beverage sucked through the sucking portion; a contaminant discharging portion formed between the sucking portion and the discharging portion to discharge the beverage flowing backward from the discharging portion to the sucking portion to the outside of the container; and a guide blocking screen formed at an intersecting portion of the sucking portion, the discharging portion, and the contaminant discharging portion to allow the sucking portion and the discharging portion to communicate with each other during the suction of the beverage and to allow the discharging portion and the contaminant discharging portion to communicate with each other during backward flowing of the beverage; a container straw having one side disposed at the inside of the container and the other side connected to the sucking portion of the contaminant backflow prevention straw; a case mounted on top of the container to have a hollow shape and including an incised portion formed on one side thereof, a storage space formed therein to accommodate and store the beverage in which contaminants are contained flowing thereto through a coupling portion connected to the contaminant discharging portion of the contaminant backflow prevention straw, and a discharging outlet formed on the underside thereof to discharge the beverage in which the contaminants are contained accommodated in the storage space to the outside; and space adjusting means mounted on the incised portion to adjust the space formed on the incised portion in accordance with the diameters of the container.

Advantageous Effects

According to the present invention, the contaminant backflow prevention straw is configured to have the contaminant discharging portion formed between the sucking portion for sucking the beverage therein and the discharging portion for discharging the beverage therethrough and the guide blocking screen formed at the intersecting portion of the sucking portion, the discharging portion, and the contaminant discharging portion, thus preventing the beverage in which contaminants are contained from being accommodated in the container while the beverage stored in the container is being sucked and avoiding the deformation of the beverage stored in the container.
Further, the contaminant backflow prevention device having the contaminant backflow prevention straw according to the present invention is configured to have the case having the storage space formed therein in such a manner as to be connected to the contaminant backflow prevention straw, thus storing and discharging the beverage in which the contaminants discharged through the contaminant discharging portion are contained therein and therefrom, without having any separate accommodation parts and also making the device easily kept and portable.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing a contaminant backflow prevention straw according to the present invention.

FIG. 2 is a sectional view showing the contaminant backflow prevention straw according to the present invention.

FIG. 3 is an enlarged view showing an example of the main parts of the contaminant backflow prevention straw according to the present invention.

FIG. 4 is an enlarged view showing another example of the main parts of the contaminant backflow prevention straw according to the present invention.

FIG. 5 is a sectional view showing an operating state of the main parts of the contaminant backflow prevention straw according to the present invention.

FIG. 6 is a perspective view showing a contaminant backflow prevention device having a contaminant backflow prevention straw according to the present invention.

FIG. 7 is a sectional view showing the contaminant backflow prevention device having the contaminant backflow prevention straw according to the present invention.

FIG. 8 is a perspective view showing another example of the contaminant backflow prevention device having the contaminant backflow prevention straw according to the present invention.

FIG. 9 is a sectional view showing the contaminant backflow prevention device having the contaminant backflow prevention straw of FIG. 6.

FIG. 10 is an enlarged view showing space adjusting means of the contaminant backflow prevention device having the contaminant backflow prevention straw of FIG. 6.

FIGS. 11 and 12 are perspective views showing the use states of the contaminant backflow prevention device having the contaminant backflow prevention straw according to the present invention.

MODE FOR INVENTION

Hereinafter, an explanation on a contaminant backflow prevention straw and a contaminant backflow prevention device having the same according to the present invention will be in detail given with reference to the attached drawings.
FIG. 1 is a perspective view showing a contaminant backflow prevention straw according to the present invention, FIG. 2 is a sectional view showing the contaminant backflow prevention straw according to the present invention, FIG. 3 is an enlarged view showing an example of the main parts of the contaminant backflow prevention straw according to the present invention, FIG. 4 is an enlarged view showing another example of the main parts of the contaminant backflow prevention straw according to the present invention, FIG. 5 is a sectional view showing an operating state of the main parts of the contaminant backflow prevention straw according to the present invention, FIG. 6 is a perspective view showing a contaminant backflow prevention device having a contaminant backflow prevention straw according to the present invention, FIG. 7 is a sectional view showing the contaminant backflow prevention device having the contaminant backflow prevention straw according to the present invention, FIG. 8 is a perspective view showing another example of the contaminant backflow prevention device having the contaminant backflow prevention straw according to the present invention, FIG. 9 is a sectional view showing the contaminant backflow prevention device having the contaminant backflow prevention straw of FIG. 6, and FIG. 10 is an enlarged view showing space adjusting means of the contaminant backflow prevention device having the contaminant backflow prevention straw of FIG. 6.
According to the present invention, a contaminant backflow prevention straw 10 includes a sucking portion 20 for sucking a beverage therein; a discharging portion 30 for discharging the beverage therethrough; a contaminant discharging portion 40 formed between the sucking portion 20 and the discharging portion 30; and a guide blocking screen 60 formed at an intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40.
The sucking portion 20 of a given length has a passage formed at the inside thereof.
That is, the sucking portion 20 serves to suck the beverage therein when the beverage stored in a container 200 is consumed through the contaminant backflow prevention straw 10.
The discharging portion 30 of a given length connected to the sucking portion 20 has a passage formed at the inside thereof in such a manner as to communicate with the passage formed inside the sucking portion 20.
That is, the discharging portion 30 serves to discharge the beverage sucked through the sucking portion 20 to the outside.
Further, the discharging portion 30 includes a corrugated portion 32 formed over a given range thereon, through which the discharging portion 30 is adjusted to allow a user to easily drink the beverage.
The contaminant discharging portion 40 of a given length, which is formed unitarily between the sucking portion 20 and the discharging portion 30, has a passage formed at the inside thereof in such a manner as to communicate with the passages formed inside the sucking portion 20 and the discharging portion 30.
In more detail, the contaminant discharging portion 40 is formed unitarily between the sucking portion 20 and the discharging portion 30 and serves to discharge the beverage flowing backward from the discharging portion 30 to the sucking portion 20 to the outside.
The guide blocking screen 60, which is formed at the intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40, has a given diameter and serves to block the passage of the contaminant discharging portion 40 or the passage of the sucking portion 20 according to the movement of the beverage.
In more detail, the guide blocking screen 60 blocks the contaminant discharging portion 40 to allow the sucking portion 20 and the discharging portion 30 to communicate with each other during the suction of the beverage and blocks the sucking portion to allow the discharging portion 30 and the contaminant discharging portion 40 to communicate with each other during backward flowing of the beverage.
At this time, an extension portion 70 is extended by a given range from the intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40 toward one side direction of the intersecting portion 50.
Instead of the guide blocking screen 60, further, a blocking member 60 a is mounted on the intersecting portion 50, and the blocking member 60 a has a spherical, curved or polygonal shape.
In more detail, the movably operating blocking member 60 a is mounted on the intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40, so that the sucking portion 20 or the contaminant discharging portion 40 can be blocked according to the user's operation.
According to the present invention, a contaminant backflow prevention device 100 includes the contaminant backflow prevention straw 10, a container straw 220 connected to the container 200 in which the beverage is stored, and a case 300 connected to the contaminant backflow prevention straw 10 to store and discharge the beverage containing contaminants sent from the contaminant backflow prevention straw 10 therein and therefrom.
In this case, the contaminant backflow prevention straw 10 has the same configuration as mentioned above, and therefore, an explanation on the straw 10 will be avoided for the brevity of the description.
The container straw 220 has one side disposed at the inside of the container 200 and the other side connected to the sucking portion 20 of the contaminant backflow prevention straw 10. Under the above-mentioned condition, the container straw 220 is freely selected from known container straws, and therefore, an explanation on the container straw 220 will be avoided for the brevity of the description.
The case 300, which is connected to the contaminant backflow prevention straw 10 to store and discharge the beverage containing contaminants sent from the contaminant backflow prevention straw 10 therein and therefrom, has configurations as shown in FIGS. 6 and 7 and as shown in FIGS. 8 and 9
As shown in FIGS. 6 and 7, first, the case 300 is mounted on top of the container 200.
Further, the case 300 has a straw passage 310 formed on one side thereof to pass the container straw 220 therethrough, a storage space 320 formed therein to accommodate and store the beverage in which contaminants are contained flowing thereto through a coupling portion 330 connected to the contaminant discharging portion 40 of the contaminant backflow prevention straw 10, and a discharging outlet 340 formed on the underside thereof to discharge beverage in which the contaminants are contained. accommodated in the storage space 320 to the outside.
That is, the case 300 is fixed to the container 200 in such a manner as to couple the center of the lower portion thereof to the top of the container 200, and further, the sucking portion 20 of the contaminant backflow prevention straw 10 and the container straw 220 are coupled to each other means of the straw passage 310 on the case 300. Furthermore, the case 300 has the space portion 320 formed at the inside thereof to store the beverage containing the contaminants sent through the contaminant discharging portion 40 therein.
Additionally, the case 300 has the discharging outlet 340 formed at the underside thereof to discharge the beverage containing the contaminants accommodated in the storage space 320 to the outside.
At this time, the discharging outlet 340 of the case 300 is open and closed by means of a cap selected from well known caps, and therefore, an explanation on the opening and closing of the discharging outlet 340 will be avoided for the brevity of the description.
Further, the case 300 has circumferential grooves 360 spaced apart from each other along the outer peripheral surface thereof in such a manner as to allow the case 300 to be rotated easily, while being detachably mounted on the container 200.
As shown in FIGS. 8 and 9, next, the case 300 is mounted on top of the container 200.
Further, the case 300 has a hollow shape and includes an incised portion 350 formed on one side thereof, the storage space 320 formed therein to accommodate and store the beverage in which contaminants are contained flowing thereto through the coupling portion 330 connected to the contaminant discharging portion 40 of the contaminant backflow prevention straw 10, and the discharging outlet 340 formed on the underside thereof to discharge the beverage in which the contaminants are contained accommodated in the storage space 320 to the outside.
That is, the case 300 is fixed to the container 200 in such a manner as to couple the inner peripheral surface thereof to the upper peripheral surface of the container 200, and further, the case 300 has the space portion 320 formed at the inside thereof to store the beverage containing the contaminants sent through the contaminant discharging portion 40 therein. Furthermore, the case 300 has the discharging outlet 340 formed at the underside thereof to discharge the beverage containing the contaminants accommodated in the storage space 320 to the outside.
At this time, the discharging outlet 340 of the case 300 is open and closed by means of a cap selected from well known caps, and therefore, an explanation on the opening and closing of the discharging outlet 340 will be avoided for the brevity of the description.
Further, the contaminant backflow prevention device includes space adjusting means 400 mounted on the incised portion 350 to adjust the space formed on the incised portion 350 in accordance with the diameters of the container 200.
The space adjusting means 400 includes a space fixing portion 410 formed at one side of the incised portion 350, a space adjusting bar 420 of a given length having fixing protrusions 422 formed sequentially on the front surface thereof and one end fixed to the space fixing portion 410, and a space adjusting portion 430 formed at the opposite side of the incised portion 350 to fix the fixing protrusions 422 of the space adjusting bar 410 thereto.
That is, the space adjusting means 400 is configured wherein one side of the space adjusting bar 420 is fixed to the space fixing portion 410 and the other side thereof is inserted into the space adjusting portion 430. Next, the case 300 is adjusted in accordance with the sizes of the container 200, and the fixing protrusions 422 of the space adjusting bar 420 are then fixed to the space adjusting portion 430.
Under the above-mentioned configuration, an explanation on the assembling procedure of the contaminant backflow prevention straw 10 and the contaminant backflow prevention device 100 will be given. below.
First, the contaminant backflow prevention straw 10 is configured to have the sucking portion 20 for sucking the beverage therein, the discharging portion 30 for discharging the beverage therethrough, the contaminant discharging portion 40 formed between the sucking portion 20 and the discharging portion 30 to discharge the beverage flowing backward from the discharging portion 30 the sucking portion 20 to the outside of the container 220, the guide blocking screen 60 formed at the intersecting portion 50 of the sucking portion 20, the discharging portion and the contaminant discharging portion 40, and the extension portion 70 extended by the given range from the intersecting portion 50 toward one side direction of the intersecting portion 50.
Further, the case 300 is configured to have the straw passage 310 formed on one side thereof, the storage space 320 formed therein to accommodate and store the beverage in which contaminants are contained therein, and the discharging outlet 340 formed on the underside thereof to discharge the beverage, in which contaminants are contained accommodated in the storage space 320 to the outside.
Next, the contaminant discharging portion 40 of the contaminant backflow prevention straw 10 is connected to the coupling portion 330 of the case 300, and the contaminant backflow prevention device 100 having the contaminant backflow prevention straw 10 is mounted on the top of the container 200 in which the beverage is accommodated.
After that, if the sucking portion 20 of the contaminant backflow prevention straw 10 is connected to the container straw 220 having one side disposed at the inside of the container 200 and the other side connected to the sucking portion 20 of the contaminant backflow prevention straw 10, the assembling process of the contaminant backflow prevention device 100 having the contaminant backflow prevention straw 10 is finished.
In this case, the assembling process of the contaminant backflow prevention device 100 having the contaminant backflow prevention straw 10 may be of course different from the above-mentioned assembling process.
Next, an explanation on the process of drinking the beverage using the contaminant backflow prevention device 100 having the contaminant backflow prevention straw 10 will be given.
If the discharging portion 30 of the contaminant back flow prevention straw 10 is inserted into a user's mouth and then pulls, the beverage accommodated in the container 200 is sucked to the user s mouth through the sucking portion 20 and the discharging portion 30.
At this time, the guide blocking shield 60 blocks the passage of the sucking portion 20 before the user's sucking operation, but if the discharging portion 30 pulls to allow the beverage accommodated in the container 200 to be sucked to the user's mouth, the guide blocking shield 60 blocks the passage of the contaminant discharging portion 40 to allow the sucking portion 20 and the discharging portion 30 to communicate with each other by means of the sucking force applied from the discharging portion 30, the flow of air circulating the extension portion 70, and the sucking force pulling from the contaminant discharging portion 40.
If the discharging portion 30 free from his or her lips, the beverage contained in has or her mouth or the discharging portion 30 is stored in the storage space 320 of the case 300 through the discharging portion 30 and the contaminant discharging portion 40.
At this time, the guide blocking shield 60 blocks the passage of the sucking portion 20 to allow the discharging portion 30 and the contaminant discharging portion 40 to communicate with each other by means of sucking force applied from the interior of the container 200, the sucking force of air circulating the extension portion 70, and the pressure applied from the discharging portion 30.
Under the above-mentioned operation, the beverage accommodated in the container can be easily drunk through the contaminant backflow prevention device having the contaminant backflow prevention straw, while the beverage in which the contaminants are contained due to the backflow thereof is being discharged to the outside.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiment 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.

Claims

1. A contaminant backflow prevention straw comprising:

a sucking portion 20 for sucking a beverage stored in a container therein;

a discharging portion 30 for discharging the beverage sucked through the sucking portion 20;

a contaminant discharging portion 40 formed between the sucking portion 20 and the discharging portion 30 to discharge the beverage flowing backward from the discharging portion 30 to the sucking portion 20 to the outside of the container; and

a guide blocking screen 60 formed at an intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40 to allow the sucking portion 20 and the discharging portion 30 to communicate with each other during the suction of the beverage and to allow the discharging portion 30 and the contaminant discharging portion 40 to communicate with each other during backward flowing of the beverage.

2. The contaminant backflow prevention straw according to claim 1, further comprising an extension portion 70 extended by a given range from the intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40 toward one side direction of the intersecting portion 50 so as to allow the rotation of the straw to be easily controlled.

3. The contaminant backflow prevention straw according to claim 1, wherein the guide blocking screen 60 is replaced with a blocking member 60 a having a spherical, curved or polygonal shape.

4. A contaminant backflow prevention device comprising:

a contaminant backflow prevention straw 10 having a sucking portion 20 for sucking a beverage stored in a container 200 therein, a discharging portion 30 for discharging the beverage sucked through the sucking portion 20, a contaminant discharging portion 40 formed between the sucking portion 20 and the discharging portion 30 to discharge the beverage flowing backward from the discharging portion 30 to the sucking potion 20 to the outside of the container 200, and a guide blocking screen 60 formed at an intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40 to allow the sucking portion 20 and the discharging portion 30 to communicate with each other during the suction of the beverage and to allow the discharging portion 30 and the contaminant discharging portion 40 to communicate with each other during backward flowing of the beverage;

a container straw 220 having one side disposed at the inside of the container 200 and the other side connected to the sucking portion 20 of the contaminant backflow prevention straw 10; and

a case 300 mounted on top of the container 200 and comprising a straw passage 310 formed on one side thereof to pass the container straw 220 therethrough, a storage space 320 formed therein to accommodate and store the beverage in which contaminants are contained flowing thereto through a coupling portion 330 connected to the contaminant discharging portion 40 of the contaminant backflow prevention straw 10, and a discharging outlet 340 formed on the underside thereof to discharge the beverage in which the contaminants are contained accommodated in the storage space 320 to the outside.

5. A contaminant backflow prevention device comprising:

a contaminant backflow prevention straw 10 having a sucking portion 20 for sucking a beverage stored in a container 200 therein, a discharging portion 30 for discharging the beverage sucked through the sucking portion 20, a contaminant discharging portion 40 formed between the sucking portion 20 and the discharging portion 30 to discharge the beverage flowing backward from the discharging portion 30 to the sucking portion 20 to the outside of the container 200, and a guide blocking screen 60 formed at an intersecting portion 50 of the sucking portion 20, the discharging portion 30, and the contaminant discharging portion 40 to allow the sucking portion 20 and the discharging portion 30 to communicate with each other during the suction of the beverage and to allow the discharging portion 30 and the contaminant discharging portion 40 to communicate with each other during backward flowing of the beverage;

a container straw 220 having one side disposed at the inside of the container 200 and the other side connected to the sucking portion 20 of the contaminant backflow prevention straw 10;

a case 300 mounted on top of the container 200 to have a hollow shape and comprising an incised portion 350 formed on one side thereof, a storage space 320 formed therein to accommodate and store the beverage in which contaminants are contained flowing thereto through a coupling portion 330 connected to the contaminant discharging portion 40 of the contaminant backflow prevention straw 10, and a discharging outlet 340 formed on the underside thereof to discharge the beverage in which the contaminants are contained accommodated in the storage space 320 to the outside; and

space adjusting means 400 mounted on the incised portion 350 to adjust the space formed on the incised portion 350 in accordance with the diameters of the container 200.

6. The contaminant backflow prevention device according to claim 4, wherein the case 300 has circumferential grooves 360 spaced apart from each other along the outer peripheral surface thereof in such a manner as to allow the case 300 to be easily rotated.

7. The contaminant backflow prevention device according to claim 5, wherein the space adjusting means 400 comprises:

a space fixing portion 410 formed at one side of the incised portion 350;

a space adjusting bar 420 of a given length having fixing protrusions 422 formed sequentially on the front surface thereof and one end fixed to the space fixing portion 410; and

a space adjusting portion 430 formed at the opposite side of the incised portion 350 to fix the fixing protrusions 422 of the space adjusting bar 410 thereto.

8. The contaminant backflow prevention device according to claim 5, wherein the case 300 has circumferential grooves 360 spaced apart from each other along the outer peripheral surface thereof in such a manner as to allow the case 300 to be easily rotated.